Wireless node memory utilization for storing beamforming settings

ABSTRACT

Embodiments for a wireless node utilizing a limited memory radio frequency integrated circuit (RFIC) are disclosed. For an embodiment, the wireless node includes a plurality of antennas operative to form a plurality of wireless beams, wherein a direction of each of the plurality of wireless beams is controlled by selecting a phase and amplitude adjustment of a communication signal communicated through each of the plurality of antennas. The wireless node includes a memory that includes a first portion and a second portion, wherein phase and amplitude settings for each of the plurality of targets are stored in the first portion, and wherein alternate phase and amplitude setting are dynamically store in the second portion. Phase and amplitude settings are accessed from the first portion when the wireless node is communicating with targets. The second portion is utilized for storing alternate settings when testing wireless communication with the targets.

RELATED APPLICATIONS

This patent application is a continuation-in-part of U.S. patentapplication Ser. No. 16/174,796 filed Oct. 30, 2018, which iscontinuation patent application of U.S. patent application Ser. No.15/382,682 filed Dec. 18, 2016 and granted as U.S. Pat. No. 10,148,557,which claims priority to U.S. Provisional Patent Application Ser. No.62/273,381, filed Dec. 30, 2015.

TECHNICAL FIELD

The disclosed embodiments relate to wireless communication networks andin particular to link maintenance of a wireless node utilizing a limitedmemory radio frequency integrated circuit (RFIC).

BACKGROUND

Most IP traffic is carried on fiber optic or cable networks. This workswell when the cable infrastructure is already present or can be easilyinstalled. However, there are many locations where it is either notpractical or too expensive to dig up streets or run cables overhead. Toalleviate this problem, wireless networks have been proposed to extendthe reach of the network to locations that cannot be connected byphysical cables.

In some wireless networks, beamforming is used on the transmitter and/orreceiver side to improve the communication link. However, due to thechanging nature of radio frequency communications, the beamformingparameters used by the transmitter and receiver are not static. Giventhis problem, there is a need for improved techniques to dynamicallyselect new beamforming parameters to improve communication between nodesin wireless communication network.

SUMMARY

An embodiment includes a wireless node. The wireless node includes aplurality of antennas operative to form a plurality of wireless beamsdirected to a plurality of targets, wherein a direction of each of theplurality of wireless beams is controlled by selecting a phase andamplitude adjustment of a communication signal communicated through eachof the plurality of antennas. The wireless node further includes amemory, the memory including a first portion and a second portion,wherein phase and amplitude settings for each of the plurality oftargets are stored in the first portion, and wherein alternate phase andamplitude setting are dynamically store in the second portion. Acontroller of the wireless node is operative to access phase andamplitude settings from the first portion of the memory when thewireless node is communicating with one or more of the plurality oftargets, and utilize the second portion of memory for storing andaccessing the alternate phase and amplitude settings when testingwireless communication with one or more of the plurality of targets.

An embodiment includes a method. The method includes forming, by aplurality of antennas of a wireless node, a plurality of wireless beamsdirected to a plurality of targets, wherein a direction of each of theplurality of wireless beams is controlled by selecting a phase andamplitude adjustment of a communication signal communicated through eachof the plurality of antennas, storing, in a memory, the memory includinga first portion and a second portion, phase and amplitude settings foreach of the plurality of targets in the first portion, and dynamicallystoring alternate phase and amplitude setting in the second portion,accessing, by a controller, phase and amplitude settings from the firstportion of the memory when the wireless node is communicating with oneor more of the plurality of targets, and utilizing, by the controller,the second portion of memory for storing and accessing the alternatephase and amplitude settings when testing wireless communication withone or more of the plurality of targets.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a point-to-point wireless communication network inaccordance with some disclosed embodiments;

FIG. 2A illustrates a number of possible transmit and receivebeamforming directions between a destination node and a client node in awireless communication network in accordance with some disclosedembodiments;

FIG. 2B illustrates how training signals are appended to an IP datapacket for transmission and reception with different beamformingdirection pairs in accordance with some disclosed embodiments;

FIG. 3 shows a node that includes memory for storing beamformingsettings of a plurality of antennas of the node, according to anembodiment.

FIG. 4 shows another node that includes memory for storing beamformingsettings of a plurality of antennas of the node, according to anembodiment.

FIG. 5 shows a node that includes a limited memory RFIC for storingbeamforming settings of a plurality of antennas of the node, accordingto an embodiment.

FIG. 6 show a node that include a plurality of RFICs for storingbeamforming settings and controlling beams formed by a plurality ofantennas of the node, according to an embodiment.

FIG. 7 is a flow diagram of steps performed by a transmitter to appendtraining signals to an IP data packet in accordance with some disclosedembodiments;

FIG. 8 is a flow diagram of steps performed by a receiver to receive IPdata packets and to test other transmit/receive beamforming directioncombinations or to re-acquire synchronization with a network if aconnection is lost in accordance with some disclosed embodiments.

FIG. 9 is a block diagram of a transmitting node, a receiving node, anda central controller, according to an embodiment.

FIG. 10 is a flow chart that includes acts of a method, according to anembodiment.

FIG. 11A shows a transmitter and a receiver of a wireless network,wherein micro-routes are formed between the first node and the secondnode, according to an embodiment.

FIG. 11B shows a first node and a second node of a wireless network,wherein micro-routes between the first node and the second node arecharacterized, according to an embodiment.

FIG. 12A shows a transmitter and a receiver of a wireless network,wherein a single micro-route can be formed between the first node andthe second node for multiple beam directions, according to anembodiment.

FIG. 12B shows micro-routes being identified by clustering measured linkqualities for multiple beam directions, according to an embodiment.

FIG. 13 shows a table of measured qualities of micro-routes, accordingto an embodiment.

FIG. 14 shows a primary lobe and side lobes of a beam-formed signal,according to an embodiment.

FIG. 15 shows a table of measured qualities of micro-routes, and furthershows measured qualities that could represent a primary lobe and sidelobes of a beam-formed signal, according to an embodiment.

FIG. 16 shows a primary lobe and side lobes of a beam-formed signal, andfurther shows a possible signal of a separate micro-route, according toan embodiment.

FIG. 17 shows a first table that lists a measured link quality for eachof five micro-routes, and lists a level of correlation with a firstmicro-route at a time T1, a second table that lists a measured linkquality for each of the five micro-routes, and lists a level ofcorrelation with a first micro-route at a time T2, according to anembodiment.

FIG. 18 shows a first node and a second node of a wireless network,wherein micro-routes between the first node and the second node arecharacterized in two transmit and receive directions, according to anembodiment.

FIG. 19 is a flow chart that includes acts of a method of characterizingmicro-links between a first node and a second node, according to anembodiment.

FIG. 20 is a flow chart that includes acts of a method of clusteringmeasured signal qualities of micro-routes, according to an embodiment.

FIG. 21 is a flow chart that includes acts of a method selectingmicro-links for communication between a first node and a second node ofa wireless network, according to an embodiment.

FIG. 22 shows a transmitting node and a receiving node located proximateto a traffic intersection, and implementation of pattern detection thatis used for micro-route characterization and selection, according to anembodiment.

FIG. 23 shows a transmitting node, a receiving node, and a cloud server,according to an embodiment.

DETAILED DESCRIPTION

FIG. 1 shows one embodiment of a point-to-point wireless communicationnetwork. The network 100 includes a number of destination nodes (DN) 102a, 102 b, 102 c, 102 d, etc. and a number of client nodes (CN) 104 a,104 b, etc. The destination nodes transmit IP packets between themselvesand the client nodes. The client nodes transmit and receive IP packetsbetween themselves and the destination nodes as well as to a number ofend users 106 (such as, but not limited to, wireless enabled devicesincluding computers, tablets, smart phones, household appliances, or anyother device capable of transmitting and receiving wireless IP data).The destination nodes 102 are typically mounted on utility poles or onbuildings and transmit point-to-point wireless signals approximately200-300 meters, depending on conditions. The client nodes 104 aregenerally located in retail/office establishments or in homes in orderto transmit and receive IP packets to and from the end users. In oneembodiment, the IP packets are sent according to a standardized protocolsuch as IEEE 802.11ad. However, it will be appreciated that any numberof other IP protocols such as WiMAX 802.16 could be used.

In the network 100, at least one destination node (e.g., node 102 a) iscoupled to a physical cable that carries IP data to and from a computercommunication link 108 (e.g., the Internet or a private communicationlink). IP packets that are destined for an end user 106 are receivedfrom the communication link and are transmitted via one or more routesto the client node 104 b, which is in communication with the end user106. For example, packets may be sent via a route including nodesDN₁->DN₃->CN₁ or via a second route including nodes DN₁->DN₂->CN₁depending on the radio frequency path conditions that may exist at anytime. For an embodiment, a route include multiple nodes, which is not tobe confused with a micro-route which included direct and indirectpropagation paths between two nodes within intervening nodes.

In one embodiment, transmissions are carried on a nonregulated 60 GHzradio frequency spectrum band. At these frequencies, the ability totransmit and receive packets is easily influenced by changingatmospheric conditions (wind, rain, etc.) or by interfering objects(e.g., buses, tree limbs, or other objects passing in and out of theline of sight). Therefore, the best route to complete a communicationlink between a transmitting and a receiving node in the network maychange over time.

In the embodiment shown, a cloud controller computer 110 includes adatabase 112 that stores a list of possible routes that have beendetermined to complete a communication link between the various nodes ofthe network. The cloud computer 110 can communicate with each of thenodes by sending packets that are addressed to the nodes in order tocontrol the overall operation of the network. In one embodiment, when anIP packet is to be sent to an end user on the network, the cloudcomputer informs the nodes which route to use.

In order to improve the communication path between each of the nodes, toreduce interference, and to increase the throughput of the network, thedestination and client nodes generally include multiple antennas thatcan be used to control the transmit and receive directions of the nodeby beamforming. As will be appreciated by those skilled in the art ofradio frequency communications, the radio frequency signals transmittedby each of the antennas can be selectively delayed by beamformingtechniques in order to direct the main lobe (i.e., the bulk of thetransmitted signal power) in a desired direction. Similarly, signalsreceived by the antennas can be delayed and summed using beamformingtechniques to change the effective listening direction of the receiver.In the embodiment shown in FIG. 1, destination node DN₁ 102 a canbeamform its transmitted and received signals in a number of differentdirections 103 a, 103 b, 103 c. Similarly destination node DN₃ 102 c canbeamform its transmitted and received signals in directions 103 d and103 e. The best communication link between destination nodes DN₁ and DN₃is determined by selecting the best transmit and receive beamformingdirections for each node in order to complete the communication link.The best communication link between nodes may not always be when thetransmit and receive beamforming directions are aligned along the lineof sight.

As discussed above, the best possible transmit path between two nodes ina point-to-point wireless network may vary over time. FIG. 2A shows adestination node 200 and a client node 202 that can communicate via anumber of different micro-routes defined by a corresponding number ofbeamforming direction pairs. A micro-route can be physical path thatrepresents the line of sight propagation of an electromagnetic wave or apath corresponding to a specific reflection. It can also be a virtualroute corresponding to a beamforming vector. Here the virtual route canbe composed of two or more physical paths appropriately phase-combinedat the transmitter (Tx) and/or the receiver (Rx). In the example shown,the destination node 200 can communicate with the client node 202 usinga number of beamforming directions 204 a, 204 b, or 204 c. Similarly,the client node 202 can communicate with the destination node 200 in anumber of beamforming directions 206 a, 206 b, or 206 c. In practice,each node may have a greater number of transmit and receive beamformingdirections (usually a prime number but not required). Not allbeamforming directions may allow a communication link to be completedbetween the nodes. In the example shown, the destination node 200 andthe client node 202 communicate using the TX/RX beamforming pair 204 b,206 b.

At some point in time, atmospheric conditions may change or an obstacle(bus, tree limb, etc.) may come between the nodes 200 and 202 such thatthe communication link that uses the TX/RX beamforming pair 204 b, 206 bis not the optimal pair to use for communication between the links. Inthis case, the nodes should switch to another TX/RX beamforming pair(micro-route) that has been determined to complete a communication linkbetween the nodes. For example, the TX/RX beamforming pair 204 a, 206 amay provide a more robust communication link than the beamforming pairthat is currently in use.

In one embodiment, if a communication link between the nodes is brokenor suspended, then each of the nodes in the link will try to reestablishthe link using one or more of the remaining micro-routes that have beendetermined to work between the nodes. Each of the nodes contains a listof micro-routes (e.g., beamforming directions) that can be tried todetermine whether a link can be reestablished. The links in the list aretried according to a predetermined protocol in order to determinewhether the link can be re-established. If a link can be reestablishedvia a new micro-route (e.g., using the TX/RX beamforming pair 204 a, 206a), then communication can continue using the new micro-route.

In some cases, a particular micro-route may provide a bettercommunication link than the one that is currently in use even though thecurrent link is not broken or disrupted. In one embodiment, eachmicro-route that has been determined to complete a communication linkbetween the nodes is periodically tested. Metrics for the alternatemicro-routes, such as bit error rate, signal-to-noise ratio,signal-to-interference ratio or others, are determined for the alternatemicro-routes and compared with metrics for the micro-route that iscurrently in use. If another micro-route has better metrics than themicro-route that is currently in use, then the nodes will switch to theother micro-route. FIG. 2B illustrates one mechanism by which the nodesof a point-to-point wireless communication network can periodically testalternative micro-routes that have been determined to be useful incommunicating between the nodes. In this embodiment, test signals areappended to IP data packets that are transmitted between the nodes. Thetest signals are transmitted and received using the TX/RX beamformingpairs for the alternative micro-routes that have been identified tocomplete the communication link between the nodes.

In the example shown, an IP data packet 300 transmitted from a nodeincludes header information 302 and data information 304, as isconventional in packetized IP communication protocols. In addition, theIP data packet 300 includes a number of training signals (TS) 306 a, 306b, 306 c . . . that are transmitted in different beamforming directions.

In one embodiment, if the transmitting node has N possible transmitbeamforming directions that will work in micro-routes with a receivingnode and the receiving node has N possible receive beamformingdirections, then the data packet includes N² training signals 306 wherea training signal is transmitted N times in each transmit beamformingdirection. In the example shown in FIGS. 2A and 2B, transmittingdestination node 200 has three transmit beamforming directions indicatedby TX1, TX2, and TX3. Similarly, receiving client node 202 has threereceive beamforming directions indicated by RX1, RX2, and RX3.

As shown, a signal 350 is received by the receiving node on the currentmicro-route that allows the receiving node to capture the headerinformation and data in the IP data packet 300. The receiving node thensequentially changes its receive beamforming directions to determinewhether it can detect the training signals being sent from thetransmitter with better link metrics. In the example illustrated, thetransmitter and receiver each have three possible transmit and receivebeamforming directions. Therefore the training signals are transmittedthree times in direction TX1, followed by three times in direction TX2and three times in direction TX3. This allows the receiving node to testits receive beamforming directions RX1, RX2, RX3 against each of thepossible transmit beamforming directions.

If a training signal is detected, the received signal is analyzed todetermine whether the link metrics associated with the received signalare better than those of the current micro-route in use. If so, thereceiving node sends a signal to the transmitting node that the currentmicro-route should be changed to a new micro-route using the TX/RXbeamforming pair that provides the best communication link.

In another embodiment, not every combination of transmit and receivebeamforming directions is compared to the others to determine the bestpossible TX/RX beamforming pair. In this embodiment, training signalsare sent via the pre-determined micro-routes that have been determinedto complete a communication link between the nodes, e.g., TX1/RX1 (204a-206 a), TX2/RX2 (204 b-206 b), TX3/RX3 (204 c-206 c). If one of thesepredetermined micro-routes has better communication metrics than themicro-route that is currently in use between the nodes, then thereceiving node sends a signal back to the transmitting node that futurecommunications should take place on this new micro-route.

In yet another embodiment, a predetermined number of transmit andreceive beamforming directions are tried that vary slightly from thetransmit and receive beamforming directions currently in use. Forexample, if the transmitting node is transmitting in direction A and thereceiving node is receiving in direction B, then the transmitter maysend two training signals in directions A+0.5 degrees and A-0.5 degrees(or some other offset). The receiving node will try to receive thetraining signals with receive beamforming directions B+0.5 degrees andB-0.5 degrees (or some other offset). The number of differentbeamforming tests to try can be fixed by the communication protocol orcan be transmitted to the receiver as part of the IP data packet. If anyof these transmit/receive beamforming combinations provide betterchannel metrics, the receiving node signals the transmitting node andthe transmit/receive beamforming pair that is used to communicatebetween the nodes can be updated.

In one embodiment, not all IP packets transmitted between the nodesinclude the training signals used to test the alternate micro-routes.For example, the training signals can be sent periodically by packetnumber (e.g., every 50th or 100th packet). Alternatively, trainingsignals can be appended to, or included in, packets based on time, suchas every 50 or 100 milliseconds (rounded to time at which the nextpacket is sent).

In one embodiment, communication protocols such as IEEE 802.11ad aremodified to provide for the addition of the training signals to beperiodically added to the IP packets that are transmitted between nodes.In addition, the protocol is adjusted to allow for the nodes tocommunicate between themselves when a TX/RX beamforming pair isdetermined to provide a better communication link than the TX/RXbeamforming pair associated with the micro-route that is currently inuse.

FIG. 3 shows a node 320 that includes memory 340 for storing beamformingsettings of a plurality of antennas of the node 320, according to anembodiment. As shown, the wireless node 320 includes a plurality ofantennas (Antenna 1-Antenna N) operative to form a plurality of wirelessbeams directed to a plurality of targets (Target 1, Target 2, Target 3,Target K). For an embodiment, the direction of each of the plurality ofwireless beams is controlled by selecting a phase and amplitudeadjustment of a communication signal communicated through each of theplurality of antennas.

The wireless node 320 includes a baseband portion 315 that operates toprocess baseband signals for either transmission or after reception. AnRF (radio frequency) chain 326, 328 is associated with each of theplurality of antennas. Each RF chain 326, 328 includes a frequencyup-conversion if the wireless node is transmitting a wireless signal ora frequency down-conversion if the wireless node is receiving a wirelesssignal. The RF chains 326, 328 can each also include amplifiers and/orfilters. Each RF chain further includes a phase and amplitude adjuster327, 329 which adjust the phase and amplitude of signals passing throughthem for the purpose of providing adjustability of the direction of thewireless beams formed by the plurality of antennas.

As shown, for an embodiment, the wireless node 320 further includes thememory 340, wherein the memory 340 including a first portion 341 and asecond portion 342. For an embodiment, phase and amplitude settings foreach of the plurality of targets (Target 1, Target 2, Target 3, TargetK) are stored in the first portion 314, and alternate phase andamplitude setting are dynamically store in the second portion 342. Thatis, when the wireless node 320 attempts to communicate with a particulartarget, the phase and amplitude settings for each of the phase andamplitude adjusters associated with each of the plurality of antennasare accessed from the first portion 314 for the particular target. Thatis, a specific phase and amplitude setting for each of the K targets isstored in the first portion 314 of the memory 340 for quick and easyaccess.

The wireless node 320 further includes a node controller 325. For anembodiment, the node controller 325 is operative to access phase andamplitude settings from the first portion 341 of the memory 340 when thewireless node 320 is communicating with one or more of the plurality oftargets (Target 1, Target 2, Target 3, Target K). Further, for anembodiment, the node controller 325 is operative to utilize the secondportion 342 of the memory 340 for storing and accessing the alternatephase and amplitude settings when testing wireless communication withone or more of the targets (Target 1, Target 2, Target 3, Target K).That is, the phase and amplitude settings of the first portion 341 ofthe memory 340 are retrieved when the wireless node 320 is tocommunicate with a specific one of the targets (Target 1, Target 2,Target 3, Target K). However, the second portion 342 can be utilizedwhen testing different phase and amplitude settings.

For an embodiment, the wireless node 320 utilizes an RFIC (radiofrequency integrated circuit). For an embodiment, the RFIC provide thecapabilities of the RF chains, the phase and amplitude settings, andfurther includes memory for storing the phase and amplitude settings foreach of the plurality of antennas. However, for at least someembodiments, the memory of the RFIC is limited. There can be a largenumber of possible phase and amplitude settings. Further, there can be alarge number of RF chains. As a result, storing all the possiblecombinations of phase and amplitude settings for each of the RF chainscan be prohibitively large. For example, the memory of the RFIC may onlyhave the ability to store information for only 100 beams. However, with,for example, 64 possible phase and amplitude settings for 32 antennas,allows for substantially more than 100 beams. The described embodimentsinclude storing set phase and amplitude settings for the say K differenttargets which is typically is less than the 100 that can be stored. Foran embodiment, the first portion of the memory of the RFIC is dedicatedto storing the phase and amplitude settings for the K targets, and thesecond portion of the memory (also referred to as the scratch-padportion of the memory) is dedicated to alternate phase and amplitudesettings that can be tested for better phase and amplitude settings forone or more of the K targets.

For an embodiment, the node controller 325 is further operative toreplace phase and amplitudes settings of the first portion of the memoryfor one or more of the target when alternate phase and amplitudesettings of the second portion of the memory are determined to be betterduring the testing of the wireless communication with one or more of thetargets. For an embodiment, the test includes tuning the beam directionto one or more targets by finely tuning the phase and amplitude settingsof the beam that is directed to the one or more targets. The fine-tunedsettings are generated and stored within the second portion of thememory. If the tuned setting is determined to be better, then thefine-tuned settings replace the original or prior settings in the firstportion of the memory. Once transferred to the first portion of thememory, the fine-tuned settings can be overwritten in the second portionof the memory for testing another beam direction.

As described, an embodiment further includes selecting the alternatephase and amplitude settings to tune a beam directed to a first targetby a first threshold, and storing the alternate phase and amplitudesettings in the second portion of the memory. The phase and amplitudesettings of an adjustment to a beam direction can be tested bytransmitting a training signal through the tuned beam. That is, for anembodiment, the wireless node further operates to transmit a firsttraining signal while the beam directed to the first target is tuned bythe first threshold. The receiving target can measure a quality of thesignal (link quality) that includes the training signal that wastransmitted through the tuned beam. For an embodiment, the receivingtarget transmits the link quality back to the wireless node. For anembodiment, the link quality is communicated to a central controller,thereby providing the wireless node access to the link quality. For anembodiment, the wireless node further operates to receive a wirelesslink quality indicator from the first target indicating a quality ofreception of the first training signal. For an embodiment, tuning thebeam includes selecting the phase an amplitude settings of each of theRF chains of the wireless node to tune or deviate the direction of thebeam of formed by the plurality of antennas of the wireless node.Deviation by greater than a threshold includes the direction of the beamdeviating (such as the angle of direction) by greater than a threshold.

For an embodiment, the alternate phase and amplitude selections can beretrieved from a memory or storage located elsewhere. For example, thealternate phase and amplitude selections can be retrieved from anupstream controller. The alternate phase and amplitude selections cancorrespond to an alternate micro-route, or to a tuning of an existingbeam direction. Once retrieved from the memory located elsewhere, thealternate phase and amplitude selections can be stored in the secondportion of the memory of the wireless node for use in testing thealternate micro-route or tuned beam directions to see if they workbetter than the present phase and amplitude settings for a particulartarget. If better, the alternate phase and amplitude settings aretransferred from the second portion of the memory of the wireless nodeto the first portion of the memory of the wireless node.

As previously described, for an embodiment, the wireless node is furtheroperative to replace the phase and amplitude setting for the firsttarget within the first portion of the memory with the alternate phaseand amplitude settings when the received link quality indicatorindicates that the alternate phase and amplitude settings provides abetter quality wireless link between the wireless node and the firsttarget than the phase and amplitude setting for the first target.

FIG. 3 additionally shows a frame 391 that depicts over time operationof the wireless node. For an embodiment, the frame includes a transmitportion 392 and a receive portion 393. For an embodiment, the wirelessnode writes new adjusted phase and amplitude settings for a beamdirection to the first portion of the memory during, for example, thetransmit portion of the frame, and then accesses and uses the newsettings from the first portion during reception of wireless signalsfrom the target during the receive portion of the frame. Clearly analternate embodiment includes storing new settings to the first portionof the memory during reception and accessing and using the new settingsduring transmission to the target.

wireless node includes frames, wherein the frame includes time slots,and wherein the alternate phase and amplitude settings are tested duringselected time slots of selected frames. For an embodiment, the testingof the fine-tuned beams or the micro-routes occurs within the frame withthe data transmission in the background. For an embodiment, the testingprocedures are interleaved with the data communication for the same linkor other links so as to not block the data communications. For anembodiment, the testing of the alternate phase and amplitude settings isperiodic. For an embodiment, the testing of the alternate phase andamplitude settings is adaptively performed, for example, when a wirelesslink between the wireless node and one or more of the targets is sensedto be lower than a threshold.

As will be further described, different beam directions can correspondto different micro-routes between the wireless node and a target node.For an embodiment, the phase and amplitude settings of beam directionscorresponding to multiple micro-routes between the wireless node and atarget node are stored in the first portion of the memory. The wirelessnode can then access and test which micro-route works better. Further,the wireless node can fine tune the beam directions of the multiplemicro-routes, and replace the phase and amplitude settings of the beamsof the micro-routes in the first portion of the memory when betterfine-tuned settings are determined and transferred from the secondportion of the memory to the first portion of the memory.

For at least some embodiments, the node controller is further operativeto retrieve from the first portion of the memory phase and amplitudesettings associated with a first micro-route of a plurality ofpredetermined micro-routes between the wireless node and a target nodeof the plurality of targets, and transmit packets in a first transmitbeamforming direction associated with the first micro-route between thewireless node and the target node. The node controller is furtheroperative to retrieve from the first portion of the memory phase andamplitude settings associated with a second micro-route of a pluralityof predetermined micro-routes between the wireless node and the targetnode, and transmit packets including one or more training signals in asecond transmit beamforming direction associated with the secondmicro-route of the plurality of predetermined micro-routes that isdifferent than the first transmit beamforming direction associated withthe first micro-route. Further, the node controller is operative toreceive feedback from the target node indicating that the secondmicro-route corresponding with a transmit/receive beamforming pair ofthe second transmit beamforming direction and a second receivebeamforming direction provides a better communication link than atransmit/receive beamforming pair of the first transmit beamformingdirection and a first receive beamforming direction of the firstmicro-route. That is, the stored phase and amplitude directions of knownmicro-routes are tested, and the micro-route providing the best linkquality between the wireless node and the target node is used forwireless communication between the wireless node and the target node. Aspreviously described, the different micro-routes can be predeterminedand stored within the first portion of the memory. Further, alternatephase and amplitude settings can be tested to determine better phase andamplitude settings for the micro-routes. The alternate phase andamplitude settings can be transferred from the second portion of thememory to the first portion of the memory when the alternate phase andamplitude settings are determined to provide a better link qualitybetween the wireless node and the target node. For an embodiment, eachof the plurality of predetermined micro-routes includes a singlewireless hop link between the transmitting node and the receiving nodewith no intermediate nodes. For an embodiment, the alternatemicro-routes can be retrieved from an upstream controller, and thentested by storing and retrieving the phase and amplitude adjustmentsrequired for the alternate micro-route in the second portion of thememory.

For at least some embodiments, the node controller is further operativeto retrieve from the second portion of the memory, a phase and amplitudesettings corresponding with a first fine-tuned direction and/or a secondof a transmit beamforming direction associated with a micro-route.Further, the node controller is operative to cause the wireless node totransmit a first training signal of the plurality of training signalswithin the at least one transmit packet in the first fined-tuneddirection of the transmit beamforming direction associated with themicro-route, wherein the first fine-tune direction deviates a directionof the transmit beamforming direction by a first threshold. For at leastsome embodiments, the node controller is further operative to retrievefrom the second portion of the memory, a phase and amplitude settingscorresponding with a second fine-tuned direction of a transmitbeamforming direction associated with a micro-route. Further, the nodecontroller is operative to cause the wireless node to transmit a secondtraining signal of the plurality of training signals within at least onetransmit packet in the second fine-tuned direction of the transmitbeamforming direction associated with the micro-route, wherein thesecond fine-tune direction deviates a direction of the transmitbeamforming direction by a second threshold. Further, the nodecontroller is operative to receive feedback from the target nodeindicating a communication link quality corresponding with one or moreof first fine-tuned direction of the transmit beamforming direction orthe second fine-tuned direction of the transmit beamforming direction.While the first fine-tuned direction and the second fine-tuned directionare described, it is to be understood that each of the fine-tunedirections can be individually tested to determine whether thefine-tuned direction of the second portion of the memory provides atuning of the beam direction that provides a better link quality betweenthe wireless node and the target node than the previously or currentlyexisting phase and amplitude settings stored in the first portion of thememory,

FIG. 4 shows another node that includes memory for storing beamformingsettings of a plurality of antennas of the node, according to anembodiment. The embodiment shows that anyone of the plurality of Ktarget nodes (target node 420) can similarly include a first portion 441and second portion 442 of a memory 440 for storing phase and amplitudesettings for phase and amplitude adjusters 427, 428 associated with RFchains 426, 428 associated with a plurality of antennas (Antenna1-Antenna N) of the node 420. Similarly, a node controller can utilizethe phase and amplitude settings of the first portion 441 of the memory440 for generating a wireless beam for supporting communication with thewireless node. The node 420 includes a baseband processor 415 forprocessing the baseband signals of the node 420.

FIG. 5 shows a node 520 that includes a limited memory RFIC 580 forstoring beamforming settings of a plurality of antennas (Antenna1-Antenna N) of the node 520, according to an embodiment. For anembodiment, the RFIC 580 only includes a limited amount of memory anddoes not allow for storing of all of the possible phase and amplitudesettings for all of the RF chains included within the RFIC 580. For anembodiment, the baseband processor 515 of the node 520 provides Nbaseband signals to the RFIC 580. Further, for an embodiment, the nodecontroller 525 selected phase and amplitude settings from the firstportion of the memory of the RFIC for generating a wireless beam inwhich a main lobe of the wireless beam is directed to a correspondingone of possible target nodes (Target1, Target 2, Target 3, Target 4,Target K). Further, for an embodiment, the node controller 525 selectsalternate phase and amplitude settings which are stored and can beretrieved from the second portion of the memory of the RFIC. Thealternate phase and amplitude settings can be tested to determinewhether the alternate phase and amplitude settings provide for theformation of a wireless beam that provides a better communication linkbetween the wireless node 520 and at least one of the target nodes. Ifthe alternate phase and amplitude settings do provide a bettercommunication link, then the alternate phase and amplitude setting istransferred from the second portion of the memory to the first portionof the memory for communication with the target node.

FIG. 6 shows a node 620 that include a plurality of RFICs 680, 682 forstoring beamforming settings and controlling beams formed by a pluralityof antennas (Antenna 1-Antenna N) of the node 620, according to anembodiment. As shown, this embodiment includes multiple RFICs (RFIC1-RFIC J) 680, 682. The multiple (J) RFICs support a greater number ofantennas of the node 620, and include a greater amount of total memoryavailable for storing the phase and amplitude settings of the RF chainswithin the RFICs. For an exemplary embodiment, each of the RFICsincludes N/J RF chains, and each RFIC supports N/J of the N antennas ofthe node 620. The baseband processor 615 connects N baseband signals tothe J RFICs. The node controller 625 supports the selection of the phaseand amplitude settings for generating wireless beams directed to thetargets (Target 1-Target K).

FIG. 7 is a flow diagram of steps performed by a processor in atransmitting node in accordance with one embodiment of the disclosedtechnology. Although the steps are described in a particular order forease of explanation, it will be appreciated that the steps could beperformed in a different order or that different steps could beperformed in order to achieve the functionality described.

Beginning at 702, a processor in the node prepares a data packet to besent from the node to a receiving node. The IP data packet typicallyincludes header information and data that are encoded in a manner thatis defined by the communication standard by which the network operates.At 704, the processor determines whether the packet to be sent is theNth packet that should include training signals. As mentioned above, oneembodiment sends training signals periodically such as every 100thpacket or at some other interval. If the answer at 704 is no, then theIP data packet is transmitted via the current micro-route to thereceiving node at 708.

If the answer at 704 is yes, then at 706 the training signals areappended or otherwise included in the IP data packet before the packetis sent at 708. As discussed above, when the packet including thetraining signals are sent at 708, the direction of the transmitbeamforming is changed with the training signals in order to test thevarious micro-routes.

At 710, the processor in the transmitting node determines if a feedbacksignal has been received from the receiving node that indicates that oneof the alternate micro-routes provides a better communication link thanthe current micro-route in use between the nodes. If the answer at 710is yes, then at 712 the processor in the transmitting node changes itstransmit beamforming direction to a direction associated with the bettermicro-route. If the answer at 710 is no, then processing returns to 702and the next packet to be transmitted to the receiving node is prepared.

FIG. 8 shows a number of steps performed by a processor in a receivingnode in accordance with some disclosed embodiments. Although the stepsare described in a particular order for ease of explanation, it will beappreciated that the steps could be performed in a different order orthat different steps could be performed in order to achieve thefunctionality described.

Beginning at 802, a processor in a receiving node determines if a packethas been received using the receive beamforming direction of a currentmicro-route. If the answer at 802 is no, then the processor determinesif a timeout limit period has expired at 804. The timeout limit periodis a predefined period during which at least one signal should have beenreceived from a transmitter in the network. If the timeout limit periodhas not expired, then processing returns to 802 to check again whetheran IP data packet has been received.

If the timeout limit period has expired and the receiving node did notreceive an IP data packet, then the processor in the receiver changesits receive beamforming direction to a direction associated with anothermicro-route. At 808, the processor determines whether an IP data packetis detected. If so, the IP data packet is processed in a conventionalmanner at 812 before processing returns to 802 in order to receive thenext packet.

If no packet is received at 808 after the receiving node has changed itsreceive beamforming direction, the processor determines at 810 whetherall the receive beamforming directions associated with the micro-routesfor which a communication link can be established with the transmittinglink have been tested. If not, processing returns to step 806 and a newreceive beamforming direction associated with a different micro-route istried.

If all the beamforming directions associated with the differentmicro-routes have been tried at 810, then the processor in receivingnode assumes that a connection has been lost to the network and begins aprocess of reestablishing synchronization with a transmitting node anddetermining the best micro-routes to use with the transmitting node at814.

If an IP data packet is received at 802, the processor in the receivingnode processes the packet at 820 in a conventional fashion. In addition,the processor determines at 822 whether the packet received is the Nthpacket that should contain the training signals. If the IP data packetis not the Nth packet containing the training signals, then processingreturns to 802 to await the arrival of the next IP data packet.

If the packet received is the Nth data packet or otherwise contains thetraining signals, the data received for the data packet is analyzedusing different receive beamforming parameters to, in effect, listen forthe training signals in a number of different directions. In oneembodiment, the receive beamforming parameters required to change thelistening direction of the receiving node are changed in real timebefore the signals are received at the receiving node's antennas. Aswill be understood by those of ordinary skill in the radiocommunications field, the receiving node typically includes a memory inwhich digitized radio frequency signals are stored. These stored signalsare analyzed with different beamforming delays and weights toessentially look at the stored data in different listening directions inorder to detect the training signals.

At 826, the processor in the receiving node determines whether anytraining signals are detected in the various receive beamformingdirections. If so, the processor determines one or more link metricsbased on the received training signals at 830. Such metrics can includesignal-to-noise ratio, signal-to-interference ratio, bit error rates,and other measures of link quality.

If no training signal has been detected or after a detected trainingsignal has been analyzed, the processor determines at 828 whether allthe receive beamforming directions have been tested. If not, processingproceeds to 824 and the next receive beamforming direction is tested. Ifall the beamforming directions have been tested, processing proceeds to832 where the receiving node informs the transmitting node whichtransmit/receive beamforming direction pair produced the bestcommunication link metrics. That transmit/receive beamforming pairshould then be used in future communications between the nodes.

In one embodiment, the signal sent from the receiving node to thetransmitting node tells the transmitting node which transmitsbeamforming direction it should use as well as which receive beamformingdirection the receiver will use. In another embodiment, the signalingscheme is characterized by no signal being sent if the best micro-routeis the same as the micro-route that is currently being used. Therefore,if the transmitter does not receive any feedback signal, it continues touse the current micro-route. Of course, other signaling schemes could beused.

In some embodiments, a back-up or default micro-route beamforming pairis used when link conditions change. The list of back-up micro-routescan be predetermined based on previously attempted transmit and receivebeamforming directions as well as a corresponding communication linkpath quality assessment. Such a list can be stored at the nodes or canbe stored at the cloud controller computer or both. Alternatively, aback-up micro-route can be defined as the micro-route with the highestpercentage “on time” except for the micro-route currently in use. Iflink conditions vary, both the transmitter and receiver can attempt toswitch to a back-up micro-route to maintain communications. Data arekept for each micro-route that is used to communicate between the nodes.The micro-route with the greatest duration or time in use can thereforebe selected as the back-up micro-route. The micro-route with the secondhighest percentage on time can be defined as the second back-upmicro-route etc. In this manner, the transmitter and receiver will bothknow which micro-routes have been successful in allowing communicationbetween the nodes and can try those micro-routes before undertaking amicro-route testing process.

In some cases, nodes in the network may not have any traffic for eachother. Therefore, keep alive (KA) message are periodically transmittedbetween the nodes to test the communication link. Micro-route testingroutines or data can be included with the KA messages in order to setthe best transmitter and receiver beamforming directions.

An embodiment includes a wireless communication network. The wirelessnetwork includes a transmitting node and a receiving node eachconfigured to transmit and receive IP data packets between thetransmitting node and the receiving node via a number of micro-routesdefined in part by a transmit beamforming direction and a receivebeamforming direction, wherein the transmitting node is configured totransmit IP data packets including one or more training signals that areto be transmitted in a direction that is different than a transmitbeamforming direction used in a current micro-route between thetransmitting node and the receiving node, and wherein the transmittingnode is further configured to receive feedback from the receiving nodeindicating that a transmit/receive beamforming direction pair associatedwith an alternate micro-route provides a better communication link thana transmit/receive beamforming direction pair associated with thecurrent micro-route and to change the transmit beamforming directionused by the transmitting node to the transmit beamforming directionassociated with the alternate micro-route.

For an embodiment, the training signals are included in every Nth IPdata packet. For an embodiment, the transmitting node has N transmitbeamforming directions and the receiving node has N receive beamformingdirections associated with the micro-routes between the nodes, andwherein the IP data packet includes N² training signals. For anembodiment, the transmitting node and the receiving node have Nmicro-routes that can complete a communication link between the nodesand wherein the IP data packet includes N training signals. For anembodiment, the number of training signals transmitted is fixed and thebeamforming directions of the training signals differ by predeterminedincrements from the transmit beamforming direction associated with thecurrent micro-route.

An embodiment includes a wireless communication network. The wirelesscommunication network includes a transmitting node and a receiving nodeeach configured to transmit and receive IP data packets between thetransmitting node and the receiving node via a number of micro-routesdefined in part by a transmit beamforming direction and a receivebeamforming direction, wherein the receiving node is configured toreceive IP data packets including one or more training signals that areto be received in a direction that is different than a receivebeamforming direction used in a current micro-route between thetransmitting node and the receiving node, and wherein the receiving nodeis further configured to send feedback to the transmitting nodeindicating that a transmit/receive beamforming direction pair associatedwith an alternate micro-route provides a better communication link thana transmit/receive beamforming direction pair associated with thecurrent micro-route and to change the receive beamforming direction usedby the receiving node to a receive beamforming direction associated withthe alternate micro-route.

For an embodiment, the transmitting node has N transmit beamformingdirections and the receiving node has N receive beamforming directionsassociated with the micro-routes between the nodes, and wherein the IPdata packet includes N² training signals. For an embodiment, thetransmitting node and the receiving node have N micro-routes that cancomplete a communication link between the nodes and wherein the IP datapacket includes N training signals.

An embodiment includes a method of operating a wireless communicationnetwork. The method includes transmitting IP data packets between atransmitting node and a receiving node via a number of micro-routesdefined in part by a transmit beamforming and a receive beamformingdirection, periodically transmitting an IP data packet including one ormore training signals that are to be transmitted in a direction that isdifferent than a transmit beamforming direction used in a currentmicro-route that is used between the transmitting node and the receivingnode, receiving feedback at the transmitting node indicating that atransmit/receive beamforming direction pair associated with an alternatemicro-route provides a better communication link than a transmit/receivebeamforming direction pair associated with the current micro-route, andchanging the transmit beamforming direction used by the transmittingnode to a transmit beamforming direction associated with the alternatemicro-route.

An embodiment includes a node for use in a wireless communicationnetwork. The node includes a transceiver, a plurality of antennas, abeamformer that can beamform signals transmitted and received at theplurality of antennas, a processor, and a memory. For an embodiment, thememory is for storing program instructions that are executable by theprocessor to transmit and receive IP data packets between the node and areceiving node via a number of micro-routes that are defined in part bya transmit beamforming direction and a receive beamforming direction,transmit IP data packets including one or more training signals that areto be transmitted in a direction that is different than a transmitbeamforming direction used in a current micro-route between the node andthe receiving node, receive feedback from the receiving node indicatingthat a transmit/receive beamforming direction pair associated with analternate micro-route provides a better communication link than atransmit/receive beamforming direction pair associated with a currentmicro-route, and change the transmit beamforming direction used by thenode to a transmit beamforming direction associated with the alternatemicro-route.

An embodiment includes a node for use in a wireless communicationnetwork. The nodes includes a transceiver, a plurality of antennas, abeamformer that can beamform signals transmitted and received at theplurality of antennas, a processor, and memory. For an embodiment, thememory is for storing program instructions that are executable by theprocessor to transmit and receive IP data packets between the node and atransmitting node via a number of micro-routes that are defined in partby a transmit beamforming direction and a receive beamforming direction,receive IP data packets including one or more training signals that arereceived in a direction that is different than a receive beamformingdirection used in a current micro-route between the node and thetransmitting node, transmit feedback to the transmitting node indicatingthat a transmit/receive beamforming direction pair associated with analternate micro-route provides a better communication link than atransmit/receive beamforming direction pair associated with a currentmicro-rout, and change the receive beamforming direction used by thenode to the receive beamforming direction associated with the alternatemicro-route.

An embodiment includes a node for use in a wireless communicationnetwork. The node includes a transceiver, a plurality of antennas, abeamformer that can beamform signals transmitted and received at theplurality of antennas, a processor, and a memory. For an embodiment, thememory is for storing program instructions that are executable by theprocessor to transmit and receive IP data packets between the node and areceiving node via a number of micro-routes that are defined in part bya transmit beamforming direction and a receive beamforming direction,keep a record of a duration in which a particular transmit or receivedirection is used to communicate with another node in the network,whereby the transmit or receive direction with the largest duration isselected as a back-up micro-route, and in the event that communicationis lost with another node in the network, select the beamformingdirection associated with the back-up micro-route to attempt tore-establish communications.

An embodiment includes a node for use in a wireless communicationnetwork. The node includes a transceiver, a plurality of antennas, abeamformer that can beamform signals transmitted and received at theplurality of antennas, a processor, and a memory. For an embodiment, thememory is for storing program instructions that are executable by theprocessor to transmit and receive IP data packets between the node and areceiving node via one or more of a number of micro-routes that aredefined in part by a transmit beamforming direction and a receivebeamforming direction, keep a record of a duration in which a particulartransmit or receive direction is used to communicate with another nodein the network, whereby the transmit or receive direction with thelargest duration is selected as a back-up micro-route, and periodicallyselect the beamforming direction associated with the back-up micro-routeto determine if the back-up micro-route provides a better communicationlink than a current micro-route in use.

An embodiment includes a node for use in a wireless communicationnetwork. The node includes a transceiver, a plurality of antennas, abeamformer that can beamform signals transmitted and received at theplurality of antennas, a processor, and a memory. For an embodiment, thememory is for storing program instructions that are executable by theprocessor to transmit and receive IP data packets between the node and areceiving node via one or more of a number of micro-routes that aredefined in part by a transmit beamforming direction and a receivebeamforming direction, determine when communication with the receivingnode in the wireless communication network has been lost, and attempt toreestablish communication with the receiving node using a previouslydetermined micro-route.

FIG. 9 shows a communication network that includes a transmitting node920 and a receiving node 930 configured to transmit and receive packetsbetween the transmitting node and the receiving node through one or moreof a plurality of predetermined micro-routes. For an embodiment, each ofthe plurality of predetermined micro-routes is determined by a transmitbeamforming direction and a receive beamforming direction. For at leastsome embodiments, the transmitting node 920 is configured to retrieve afirst micro-route of the plurality of predetermined micro-routes (forexample, the transmitting node can retrieve the first micro-route fromstorage (such as, storage 990) that includes the plurality ofpredetermined micro-routes). For at least some embodiments, thetransmitting node 920 is configured to transmit packets in a firsttransmit beamforming direction associated with the first micro-routebetween the transmitting node and the receiving node, transmit packetsincluding one or more training signals in a second transmit beamformingdirection associated with a second micro-route of the plurality ofpredetermined micro-routes that is different than the first transmitbeamforming direction associated with the first micro-route, and receivefeedback from the receiving node 930 indicating that the secondmicro-route corresponding with a transmit/receive beamforming pair ofthe second transmit beamforming direction and a second receivebeamforming direction provides a better communication link that atransmit/receive beamforming pair of the first transmit beamformingdirection and a first receive beamforming direction of the firstmicro-route.

For at least some embodiments, the second micro-route is selected basedupon a level of correlation between the first micro-route and the secondmicro-route. That is, the second micro-route is retrieved from storageof a plurality of available predetermined micro-routes between thetransmitting node and the receiving node. The second micro-route isselected from the plurality of available micro-routes based on the levelof correlation between the first micro-route and the second micro-route.That is, the second micro-route is selected rather than one of the otheravailable predetermined micro-routes because of the level of correlationbetween the first micro-route and the second micro-route.

For an embodiment, the plurality of predetermined micro-routes arestored in memory 690, and include micro-routes between the transmittingnode 920 and the receiving node 630 that have been previously determinedthrough a micro-route characterization process. The micro-routecharacterization can be controlled by one or more of a node controller925 of the transmitting node 920, a node controller 935 of the receivingnode 930, and/or by a central or cloud controller 910. For anembodiment, the cloud controller 910 communicates with the transmittingnode 920 and the receiving node 930, and provides at least some controlover the operation of the transmitting node 920 and the receiving node930. For at least some embodiments, the central or cloud controller 910controls the transmitting node 920 and the receiving node 930 during themicro-route determination and/or characterization process. For anembodiment, link quality measurements between the transmitting node 920and the receiving nodes 930 are measured at the receiving node through alink quality measurement 938. For at least some embodiment, link qualitymeasurements are obtained at the receiving node for differentmicro-routes as controlled by the selections of the beam direction atboth the transmitting node 920 and the receiving node 930. For anembodiment, the link quality measurements are used by the central orcloud controller 910 for determining and characterizing the micro-routesbetween the transmitting node 920 and the receiving node 930. Severalembodiments for determining, characterizing and storing the micro-routesbetween the transmitting node and the receiving node will be described.

For at least some embodiments, once the transmitting node 920 receivefeedback from the receiving node 930 indicating that the secondmicro-route corresponding with a transmit/receive beamforming pair ofthe second transmit beamforming direction and a second receivebeamforming direction provides a better communication link that atransmit/receive beamforming pair of the first transmit beamformingdirection and a first receive beamforming direction of the firstmicro-route, the transmitting node 920 changes a transmit beamformingdirection of the transmitting node 920 to the second transmitbeamforming direction associated with the second micro-route. Further,to support the second micro-route, the receiving node 930 changes to thesecond receive beamforming direction associated with the secondmicro-route.

For at least some embodiments, the transmission of packets that includeone or more training signals is periodic. For at least some embodiment,the period of the periodic transmission of packets that include trainingsignals is adaptively selected based upon one or more wireless networkparameters. For at least some embodiments, the period of the periodictransmission is based on one or more of a link quality between thetransmitting node and the receiving node, a detected change in atopology of the wireless communication network, a detected change in anenvironmental condition of the wireless communication network, adetected change in packet traffic of the wireless communication network,or a monitored condition of the wireless communication network

At least some embodiments include the transmitting node adaptivelytransmitting packets that include one or more training signals indifferent transmit beamforming directions based on at least one of alink quality between the transmitting node and the receiving node, adetected change in a topology of the wireless communication network, adetected change in an environmental condition of the wirelesscommunication network, a detected change in packet traffic of thewireless communication network, or a monitored condition of the wirelesscommunication network.

For at least some embodiments, the transmission packets that includetraining signals is adaptively determined based on statistical analysisof the transmission channel between the transmitting node and thereceiving node. For example, the link quality of the channel can bemonitored over durations of time, such as, days, weeks months or years.At certain periods of time, channel behavior can be observed. Forexample, particular channel behavior may be observed during particularperiods or times of the day, week, month or year. Based upon thestatistical analysis of the channel over time, the transmission ofpackets that include training signal can be selected to correspond whenthe training signals or likely to be useful. For example, thestatistical analysis may determine that the transmission channel betweenparticular transmitting nodes and receiving nodes is compromised onparticular times of the day, days of the week, weeks of the month, ormonths of the year. Accordingly, the statistical analysis can adaptivelycontrol the transmission of packets that include the training signals atthe identified times in which the transmission channel is likely to becompromised. For at least some embodiments, the statistical analysis isperformed at an upstream controller which at least partially controlswhen transmitting nodes transmit packets that include training signals.

For at least some embodiments, a (single) transmit packet includes aplurality of training signals. Further, for an embodiment, thetransmitting node 920 transmits different training signals of the(single) packet with different transmit beamforming directions, and thereceiving node receives the different training signals of the (single)packet with different receive beamforming directions. For an embodiment,the cloud controller 910 provides the transmitting node and thereceiving node with control over the transmission of packets thatinclude multiple training signals, and further, controls the transmitbeamforming directions of the transmitting node 920 and the receivebeamforming directions of the receiving node 930. For an embodiment, thecontrol of the receive beamforming directions of the receiving node 930is conveyed to the receiving node 930 by information included within thepacket. That is, for example, a header of the packet is received by thereceiving node 930 that include information that controls the receivebeamforming directions of the receiving node 930.

For an embodiment, the transmitting node 920 is configured to retrievetwo or more micro-routes of the plurality of predetermined micro-routes,transmit a first training signal of the plurality of training signalswithin the transmit packet in a first transmit beamforming directionassociated with a first micro-route, transmit a second training signalof the plurality of training signals within the transmit packet in asecond transmit beamforming direction associated with a secondmicro-route, and receive feedback from the receiving node indicating acommunication link quality corresponding with one or more of atransmit/receive beamforming pair of the first transmit beamformingdirection and a first receive beamforming direction, a transmit/receivebeamforming pair of the first transmit beamforming direction and asecond receive beamforming direction.

For at least some embodiments, the transmitting node is configured toreceive feedback from the receiving node indicating a communication linkquality corresponding with one or more of a transmit/receive beamformingpair of the second transmit beamforming direction and the first receivebeamforming direction, a transmit/receive beamforming pair of the secondtransmit beamforming direction and the second receive beamformingdirection.

As previously described, for an embodiment, the transmitting node isfurther configured to transmit a training packet a plurality of times ina single transmit beamforming direction, and receive feedback from thereceiving node indicating detection of reception of the training packetin at least one of a plurality of receive beamforming directions. Thatis, the transmitting node repeatedly transmits the training packets in asingle transmit beamforming direction, and the receiving node attemptsto receive the training packet over a plurality of receive beamformingdirections.

As previously described, for an embodiment, the transmitting node isfurther configured to transmit a training packet in a plurality transmitbeamforming direction, and receive feedback from the receiving nodeindicating detection of reception of the training packet in a singlereceive beamforming direction for one or more of the plurality oftransmit beamforming directions.

At least some embodiments include dithering (varying by a small (lessthan a selected threshold)) the transmit beamforming direction and/orthe receive beamforming direction. That is, for an embodiment, after apreselected micro-route has been selected, and the transmit beamformingdirection of the transmitting node 920 and the receive beamformingdirection of the receiving node 930 have been set according to theselected micro-route, either the transmit beamforming direction or thereceive beamforming direction are adjusted (fine-tune adjusted) aboutthe selected beamforming direction. The direction of either the transmitbeamforming direction or the receive beamforming direction are slightlyadjusted about the AoD (angle of departure) of the transmit beamformingdirection or about the AoA (angle of arrival) the receive beamformingdirection. For an embodiment, different training signals are transmittedwhile direction of the transmit beamforming direction or the receivebeamforming direction is adjusted.

For an embodiment, the transmitting node 920 is configured to transmit afirst training signal of the plurality of training signals within the atleast one transmit packet in a first fined-tuned direction of a transmitbeamforming direction associated with a micro-route, wherein the firstfine-tune direction deviates a direction of the transmit beamformingdirection by a first threshold. For an embodiment, the first thresholdis a deviation in the AoD of the transmit beamforming direction of lessthan a preselected amount. Further, the transmitting node 920 isconfigured to transmit a second training signal of the plurality oftraining signals within the at least one transmit packet in a secondfine-tuned direction of the transmit beamforming direction associatedwith the micro-route, wherein the second fine-tune direction deviates adirection of the transmit beamforming direction by a second threshold.For an embodiment, the second threshold is a deviation in the AoD of thetransmit beamforming direction of less than the preselected amount.Further, the transmitting node 920 is configured to receive feedbackfrom the receiving node indicating a communication link qualitycorresponding with one or more of first fine-tuned direction of thetransmit beamforming direction or the second fine-tuned direction of thetransmit beamforming direction. For an embodiment, the first and secondthreshold are selected to be greater than a minimal threshold (that is,at least some deviation of the beam directions occurs) but less thanhalf the deviation (difference between the AoD or AoA) between transmitbeamforming direction and/or receive beamforming directions of twodifferent preselected micro-routes.

For at least some embodiments, at least one of an upstream controller ora controller of the transmitting node is operative to determine theplurality of predetermined micro-routes. For an embodiment, determiningthe plurality of predetermined micro-routes includes characterizing aplurality of micro-routes between the transmitting node and thereceiving node, and storing the characterized plurality of micro-routes.For at least some embodiments, characterizing the plurality ofmicro-routes between the transmitting node and the receiving nodeincludes the upstream controller being operative to direct a first beamformed by a plurality of antennas of the transmitting node to aplurality of directions, direct a second beam formed by a plurality ofantennas of the receiving nodes to a plurality of directions for each ofthe plurality of directions of the first beam, and characterize a linkquality between the transmitting node and the receiving node for each ofthe plurality of beam directions of the first beam and each of theplurality of beam directions of the second beam. Various embodiments fordetermining and characterizing the micro-routes between the transmittingnode and the receiving node are depicted in FIGS. 8A, 8B, 9A, 9B, 10-20.

For at least some embodiments, the receiving node decodes a header of apacket received from the transmitting node, and determines a number oftraining signals included within the packet, and a number of receivebeamforming directions of the receiving node for the number of trainingsignals. For an embodiment, a node controller of the transmitting nodedetermines the number of training signals included within the packet,and the number of receive beamforming directions of the receiving nodefor the number of training signals. For an embodiment, the cloudcontroller determines the number of training signals included within thepacket, and the number of receive beamforming directions of thereceiving node for the number of training signals.

For an embodiment, the number of predetermined routes is scaled oradaptively adjusted. That is, a full scan includes selected from amongall preselected micro-routes, whereas a shortened scan includesselection of micro-routes from a scaled-down set of the preselectedmicro-routes. As will be described, for at least some embodiments,during the characterization process, characterized micro-routes areclustered, and a level of correlation between the clustered micro-routesis determined. For an embodiment, the shortened scan, or scaling of thepredetermined micro-routes that are selected from, includes scaling thepredetermined micro-routes depending upon the link quality associatedwith the micro-routes, and the level of correlation between themicro-routes. More specifically, for an embodiment, the least correlatedmicro-routes and the micro-routes having the best link quality areselected.

FIG. 10 is a flow chart that includes acts of a method, according to anembodiment. A first step 1010 includes transmitting, by a transmittingnode, transmit packets, and receiving, by a receiving node, receivepackets between the transmitting node and the receiving node through oneor more of a plurality of predetermined micro-routes, wherein each theplurality of predetermined micro-routes is determined by a transmitbeamforming direction and a receive beamforming direction. A second step1020 includes retrieving, by the transmitting node, a first micro-routeof the plurality of predetermined micro-routes. A third step 1030includes transmitting, by the transmitting node, packets in a firsttransmit beamforming direction associated with the first micro-routebetween the transmitting node and the receiving node. A fourth step 1040includes transmitting, by the transmitting node, packets including oneor more training signals in a second transmit beamforming directionassociated with a second micro-route of the plurality of predeterminedmicro-routes that is different than the first transmit beamformingdirection associated with the first micro-route. A fifth step 1050includes receiving, by the transmitting node, feedback from thereceiving node indicating that the second micro-route corresponding witha transmit/receive beamforming pair of the second transmit beamformingdirection and a second receive beamforming direction provides a bettercommunication link that a transmit/receive beamforming pair of the firsttransmit beamforming direction and a first receive beamforming directionof the first micro-route. An embodiment include changing, by thetransmitting node, a transmit beamforming direction of the transmittingnode to the second transmit beamforming direction associated with thesecond micro-route.

At least some embodiments further include adaptively transmittingpackets, by the transmitting node, that include one or more trainingsignals in different transmit beamforming directions based on at leastone of a link quality between the transmitting node and the receivingnode, a detected change in a topology of the wireless communicationnetwork, a detected change in an environmental condition of the wirelesscommunication network, a detected change in packet traffic of thewireless communication network, or a monitored condition of the wirelesscommunication network.

For at least some embodiments, a transmit packet includes a plurality oftraining signals. Further, the method further includes retrieving, bythe transmitting node, two or more micro-routes of the plurality ofpredetermined micro-routes, transmitting, by the transmitting node, afirst training signal of the plurality of training signals within thetransmit packet in a first transmit beamforming direction associatedwith a first micro-route, transmitting, by the transmitting node, asecond training signal of the plurality of training signals within thetransmit packet in a second transmit beamforming direction associatedwith a second micro-route, and receiving, by the transmitting node,feedback from the receiving node indicating a communication link qualitycorresponding with one or more of a transmit/receive beamforming pair ofthe first transmit beamforming direction and a first receive beamformingdirection, a transmit/receive beamforming pair of the first transmitbeamforming direction and a second receive beamforming direction.

At least some embodiments further include receiving, by the transmittingnode, feedback from the receiving node indicating a communication linkquality corresponding with one or more of a transmit/receive beamformingpair of the second transmit beamforming direction and the first receivebeamforming direction, a transmit/receive beamforming pair of the secondtransmit beamforming direction and the second receive beamformingdirection.

As previously described, at least some embodiments further includetransmitting, by the transmitting node, a first training signal of theplurality of training signals within the at least one transmit packet ina first fined-tuned direction of a transmit beamforming directionassociated with a micro-route, wherein the first fine-tune directiondeviates a direction of the transmit beamforming direction by a firstthreshold, transmitting, by the transmitting node, a second trainingsignal of the plurality of training signals within the at least onetransmit packet in a second fine-tuned direction of the transmitbeamforming direction associated with the micro-route, wherein thesecond fine-tune direction deviates a direction of the transmitbeamforming direction by a second threshold, and receiving, by thetransmitting node, feedback from the receiving node indicating acommunication link quality corresponding with one or more of firstfine-tuned direction of the transmit beamforming direction or the secondfine-tuned direction of the transmit beamforming direction.

As previously described, at least some embodiments include determiningthe plurality of predetermined micro-routes including characterizing aplurality of micro-routes between the transmitting node and thereceiving node, and storing the characterized plurality of micro-routes.For at least some embodiments, characterizing the plurality ofmicro-routes between the transmitting node and the receiving nodeincludes directing a first beam formed by a plurality of antennas of thetransmitting node to a plurality of directions, for each of theplurality of directions of the first beam, directing a second beamformed by a plurality of antennas of the receiving nodes to a pluralityof directions, and characterizing a link quality between thetransmitting node and the receiving node for each of the plurality ofbeam directions of the first beam and each of the plurality of beamdirections of the second beam.

As previously described, at least some embodiments the receiving nodedecodes a header of a packet received from the transmitting node, anddetermines a number of training signals included within the packet, anda number of receive beamforming directions of the receiving node for thenumber of training signals.

As described, at least some embodiments include retrieving a firstmicro-route from the plurality of predetermined micro-routes, andretrieving a second micro-route from the plurality of predeterminedmicro-routes. For an embodiment, retrieving the micro-routes includeaccessing the micro-routes from storage that includes the plurality ofpredetermined micro-routes. For at least some embodiments, the pluralityof predetermined micro-routes is determined by a characterizationprocedure in which micro-routes between the transmitting (first) nodeand the receiving (second) node are determined and characterized.

For an embodiment, once characterized, one or more of the characterizedmicro-routes is selected for wireless communication between the first(transmitting) node and the second (receiving) node. For an embodiment,upon detecting a condition (for an embodiment, the condition indicatesperformance of the micro-route of below a threshold) of a micro-routethat is being used to wirelessly communicated between nodes of thewireless network, a different micro-route is selected based on a levelof correlation between the micro-route and the different micro-route.

Micro-Routes

Micro-routes are transmission paths that are formed between wirelessnodes of a wireless network. For an embodiment, the micro-route includesa link between two nodes without any intervening nodes. Due toreal-world conditions, direct and reflective transmission paths(micro-routes) can be formed between the wireless nodes. Themicro-routes can change over time, wherein some micro-routes disappearand other are formed as conditions and the environment between thewireless nodes changes. Generally, some micro-routes are correlated(that is, the micro-routes are similar in that the same effects (suchas, interference) influence the performance of wireless communicationthrough the micro-routes), and some micro-routes are not correlated(that is, correlated less than a threshold). For an embodiment, when amicro-route is being used for wireless communication, and thatmicro-route suffers from a performance degrading effect, a different(new) micro-route is selected to replace the micro-route, wherein theselection of the different micro-route is made based on the level ofcorrelation of the micro-route to the difference micro-route. The lesscorrelated the different micro-route is to the previously selected orused micro-route, the less likely the different route is to be sufferingfrom the same performance degrading effects.

Micro-Route Analytics

Micro-route analytics deals with the processing of micro-routes. For anembodiment, the processing of micro-routes includes the identificationof the micro-routes, and characterization of the identifiedmicro-routes. For an embodiment, the micro-route analytics is performedat an upstream server that is connected to the wireless nodes, such as,at a cloud controller. For an embodiment, the micro-route analytics isperformed at a link level, for example, at one or more of the wirelessnodes. For an embodiment, the micro-route analytics is jointly performedthrough the interaction between the cloud controller and a local LA(link analytics) module at the transmit portion of the link. At leastsome of the described embodiments include processing for selecting,ordering and weeding out micro-routes to be used at the link level.

Micro-Route Correlation Detection

Micro-route correlation detection refers to the mapping of beamformingvector combinations to the actual physical paths of the link. By adefinition, a micro-route is synonymous with one of availablepropagation paths of the channel. A micro-route can correspond to aphysical path, which can be either a line of sight path or a reflectionof order one or more. Also, due to the geometry and the type ofenvironment, two unique paths (micro-routes) in the link can becorrelated. For an embodiment, an analytics module residing in the cloudor one or more of the wireless nodes identifies the level of correlationbetween micro-routes of a link between the wireless nodes. For anembodiment, correlation between identified micro-routes is determined bytesting different micro-routes over time, and determining similaritiesof the performance, and variations of the performance of the differentmicro-routes. The less the similarities between the differentmicro-routes, the less the correlation between different micro-routes.

For at least some embodiments, the micro-routes between the transmittingnode and the receiving node are monitored over time. That is, theperformance of the micro-routes is re-characterized repeatedly overtime. For at least some embodiments, the level of correlation betweenthe different micro-routes is determined by determining variations inthe performance (for example, measured link quality) between thedifferent micro-routes over the repeated characterizations. That is, thecorrelation determination includes determining whether the performanceof the different micro-routes changes similarly or differently overtime. The more correlated different micro-routes are, the more similarthe variations in the performance of the micro-routes. The lesscorrelated the different micro-routes are, the less similar thevariation in the performance of the micro-routes. Statistical processescan be used to determine the similarity or difference between differentmicro-routes over time by comparing the performance of the differentmicro-route over the repeated characterization of the performance of thedifferent micro-routes over time.

For at least some embodiments, the correlation between differentmicro-routes is determined by determining how the performance of thedifferent micro-routes is affected by a change in a network condition.Exemplary network conditions include the introduction or the eliminationof one or more interfering signals, a change in network topology (suchas, the addition or removal of a network node, or the change of locationof a network node), a change in the environment around or surroundingthe wireless network (such as, movement of, addition of, or subtractionof a physical object). If the different micro-routes are correlated,then the change in the network condition will change the performance ofthe different micro-routes similarly. If the different micro-routes arenot correlated, then the change in the network condition will change theperformance of the different micro-routes differently. Statisticalprocesses can be used to determine the similarity or difference betweendifferent micro-routes with changes in the network conditions.

Identifying Micro-Routes

FIG. 11A shows a transmitter and a receiver of a wireless network,wherein micro-routes are formed between the first node (Tx) and thesecond node (Rx), according to an embodiment. As shown, three physicalpaths (uR1, uR2, uR3) exist between the transmitter (Tx) and thereceiver (Rx). Each of the three physical paths (micro-routes) includesan angle of departure (AoD) from the transmitter (Tx) and angle ofarrival (AoA) to the receiver (Rx).

For at least some embodiments, each of the transmitter (Tx) and thereceiver (Rx) include a plurality of antennas, and are operable to formdirectional beams. The right combinations of transmit antenna beam andreceiver antenna beam directions excites one of the micro-routes if, forexample, a main lobe of a beam formed by the plurality of antennas ofthe transmitter (Tx) is directed in the vicinity of the AoD of theexcited micro-route and a main lobe of a beam formed by the plurality ofantennas of the receiver (Rx) is directed in the vicinity of the AoA ofthe excited micro-route.

For an embodiment, at the link layer (at the nodes), a beamformingacquisition procedure identifies all the beam combinations that canestablish the link between the transmitting node and the receiving node.For an embodiment, at the system level (for example, controlled by acloud server that is connected through a network to the transmittingnode and the receiving node) the beamforming acquisition procedureidentifies all the beam combinations that can establish the link betweenthe transmitting node and the receiving node.

FIG. 11B shows a first node 1110 and a second node 1120 of a wirelessnetwork, wherein micro-routes between the first node 1110 and the secondnode 1120 are characterized, according to an embodiment. For anembodiment, the first node 1110 (transmitting node) includes multipleantennas and transmits a beam-formed signal. A direction of thebeam-formed signal of the first node 1110 is adjusted to multipledirection settings. That is, the AoD of the beam-formed signal of thefirst node 1110 is different for each of the multiple directionsettings. For an embodiment, the multiple direction setting includessweeping the AoD of the first node 110 over multiple angles (multipleAoDs).

For at least some embodiments, the first node 1110 and the second node1120 include multiple sectors 1111, 1112, 1113, 1114, 1121, 1122, 1123,1124. For at least some embodiments, each sector includes a radio.Further, for an embodiment, each sector includes multiple antennas thatare operative to form beams.

For an embodiment, for each multiple beam direction settings of thebeam-formed signal of the first node 1110, a beam-formed direction ofthe second node (receiving node) 1120 is adjusted to multiple directionsettings. For each setting of the beam-formed signal of the first node1110 and beam-formed direction of the second node 1120, a link qualitycharacterization between the first node 1110 and the second node 1120 ismade. For an embodiment, the transmitting node 1110 transmits anequivalent signal at each of the beam-formed directions of the first(transmitting) node 1110. The receiving node 1120 then measures areceived signal level at each of the beam-formed directions of thesecond (receiving) node.

For an embodiment, a matrix is generated based on the beam-formeddirections of the transmitting node and the beam-formed direction of thereceiving node. This matrix can be a two dimensional matrix and a threedimensional matrix. For an embodiment, the number of elements of thematrix is dependent upon the number of beam-formed directions of thetransmitting node and the number of beam-formed directions of thereceiving node.

Channel and System Model Between Wireless Nodes

For an embodiment, an analog N×N multipath channel H between the twoN-element antenna arrays (that is, two node (transmitting node andreceiving node) having N antenna elements) is given by:

${H(\tau)} = {\sum\limits_{l = 1}^{L}{{\alpha (l)}{v\left( {\theta_{R}(l)} \right)}{v^{H}\left( {\theta_{T}(l)} \right)}{\delta \left( {\tau - {\tau (l)}} \right)}}}$

where, l Is the path index, α(l) is the complex coefficient of the pathwhich captures the relative magnitude and phase of path l, θ_(R)(l) isthe DFT (Discrete Fourier Transform) angle corresponding to the angle ofarrival of path l at the receive array, θ_(T) (l) is the DFT anglecorresponding to the angle of departure of path l at the receive array,τ(l) is the relative time delay of path l, and ν(θ) is a DFT vector withthe nth entry being exp(jnθ).

For an embodiment, mapping to a DFT angle (angular frequency) and thephysical direction is related to the array parameters and is expressedas

$\theta = {\frac{2\; \pi \; d}{\lambda}\cos \; A_{p}}$

where A_(p) is the physical direction of arrival/departure in referenceto the orientation of the array.

For a given combination of beam formers, {w_(T),w_(R)} at tx and rx, Theinput-output relationship for the link can be written as

y(t)=x(t)*{w _(R) ^(H) H(t)w _(T) }+n(t)

Now considering geometric beamforming at both Tx and Rx. The geometricbeamforming satisfies the DFT structure as well. For tx beamforming atangular frequency ϕ_(T) and rx beamforming at angular frequency ϕ_(R),the effective signal component is given by

${{v^{H}\left( \varphi_{R} \right)}{H(\tau)}{v\left( \varphi_{T} \right)}} = {{\sum\limits_{l = 1}^{L}{{\alpha (l)}\left\{ {{v^{H}\left( \varphi_{R} \right)}{v\left( {\theta_{R}(l)} \right)}} \right\} \left\{ {{v^{H}\left( {\theta_{T}(l)} \right)}{v\left( \varphi_{T} \right)}} \right\} {\delta \left( {\tau - {\tau (l)}} \right)}}} = {\sum\limits_{l = 1}^{L}{{\alpha (l)}{\exp \left( \frac{\left( {N - 1} \right)\left( {{\Delta_{T}(l)} + {\Delta_{R}(l)}} \right)}{2} \right)}{{sinc}\left( {N\; {\Delta_{T}(l)}} \right)}{{sinc}\left( {N\; {\Delta_{R}(l)}} \right)}{\delta \left( {\tau - {\tau (l)}} \right)}}}}$     when     Δ_(T)(l) = φ_(T) − θ_(T)(l)Δ_(R)(l) = θ_(R)(l) − φ_(R)$\mspace{79mu} {{{sinc}\left( {N\; \Delta} \right)} = \frac{\sin \left( {N\; {\Delta/2}} \right)}{\sin \left( {\Delta/2} \right)}}$

It is to be noted that the above analysis does not take into account anydifferential response due to change in the elevation angle of differentpaths (example: ground bounce). This means either the antenna responseis flat across the elevation angle, or paths have the same elevationangle.

For an embodiment of an antenna array, which doesn't steer acrosselevation dimension, by capturing the effect of elevation in the complexcoefficient of the path a (1), the effect of elevation can beappropriately modeled as follows:

H(τ)=Σ_(l=1) ^(L)α(l,ψ_(T)(l),ψ_(R)(l))ν(θ_(R)(l))ν^(H)(θ_(T)(l)δ(τ−τ(l))

Even for ground bounce where azimuth beamforming is optimal, theelevation response is attenuated to a considerable extent in addition tothe attenuation caused by the reflection. For example, in one of theworst cases of ground bounce effect where the antenna height is only 5 mand distance 200 m, the elevation angle will be approximately 3 degrees.With antenna array of elevation HPBW of about 10 degrees, the antennapattern at both ends jointly can suppress the ground bounce by at least3 dB. Also, the ground reflection is expected to be at least 2 dBresulting in a minimum suppression of at least 5 dB.

For an established beam combination, it can be seen that only onemicro-route will be predominantly excited. Here the effective channel isapproximated as

${h(\tau)} \approx {{\alpha \left( l^{*} \right)}{\exp\left( \frac{\left( {N - 1} \right)\left( {{\Delta_{T}\left( l^{*} \right)} + {\Delta_{R}\left( l^{*} \right)}} \right)}{2} \right)}{{sinc}\left( {N\; {\Delta_{T}\left( l^{*} \right)}} \right)}{{sinc}\left( {N\; {\Delta_{R}\left( l^{*} \right)}} \right)}{\delta \left( {\tau - {\tau \left( l^{*} \right)}} \right)}}$

where l* represents the index of the significant physical path that wasexcited by the beamformer.

FIG. 12A shows a transmitter (Tx) and a receiver (Rx) of a wirelessnetwork, wherein a single micro-route 1210 can be formed between thefirst node (TX) and the second node (RX) for multiple beam directions,according to an embodiment. That is, for example, FIG. 12A shows twodifferent beam directions (m, n) of the TX and two different beamdirections (q, p) of the RX. It is possible that different of thesecombinations of directions excite the same micro-route 1210. Anembodiment includes clustering the measured responses of multiple beamdirections which correspond with a single micro-route. That is, multiplebeam directions of the transmitting node and multiple beam directions ofthe receiving node can excited the same micro-route. At least someembodiments include clustering the measured responses of the multiplebeam directions into a single identified micro-route.

FIG. 12B shows micro-routes being identified by clustering measured linkqualities for multiple beam directions, according to an embodiment. Thenumber “1”s depicted in FIG. 12B represent link quality measurementsgreater than a threshold. If a measurement is less than the threshold, a“1” is not indicated. A first cluster 1230 includes multiple linkquality measurements for a first set of transmit beam directions andreceive beam directions. The measurements within the clusters arerelated as having link qualities greater than a link quality threshold,and as having very similar (within a threshold) beam setting directions.

A second cluster 1240 includes multiple link quality measurements for asecond set of transmit beam directions and receive beam directions. Athird cluster 1250 includes multiple link quality measurements for asecond set of transmit beam directions and receive beam directions.

For at least some embodiments, clustering multiple link qualitymeasurements includes generating a link quality matrix based on linkquality measurements between a transmitting node and a receiving nodefor multiple transmit beam directions (multiple AoDs) and for multiplereceive beam directions (multiple AoAs). Further, the clusteringincludes identifying link quality measurements having a quality betterthan a quality threshold. Further, link quality measurements of greaterthan the threshold and within an AoD range threshold and within an AoArange threshold are clustered, and each cluster is identified as asingle micro-link. That is, as shown in FIG. 12A, a single micro-routemay be formed between the transmitting node (Tx) and the receiving node(Rx) for a small (threshold) range of variations of the AoD and a small(threshold) range of variations of the AoA. For an embodiment, themeasured link qualities for small (less than a threshold) of variationsof AoD and AoA having a link quality better than the quality thresholdare clustered, and designated as a single micro-route. Once clustered,the described embodiments further include classifying the differentidentified clusters (micro-routes) as side-lobes of a micro-route or asseparate micro-routes.

Classifying Clusters

For an embodiment, acluster includes just a single link qualitymeasurement of a single transmitter AoD and a single receiver AoA. Foran embodiment, a cluster includes multiple link quality measurements ofmultiple transmitter AoD(s) and multiple receiver AoA(s).

At least some embodiments include processing based on deterministicaspects of the link geometry. At least some embodiments include one ormore of the following assumptions. A first assumption includes assuminga link budget is such that only main-lobe of the array pattern (at leaston one side) can establish the link. A second assumption includesassuming that at most, only one physical propagation path can be excitedwith any beam combination. For some embodiments with ground bounce,there can be two paths, but the ground bounce path is at least 5 dBlower. For at least some embodiments, ground bounce is still consideredseparately in the analysis. A second assumption includes assuming with aCPHY, a minimum SNR of −8 dB is required to establish the link. Assuming10 dB requirement for MCS 8 (modulation and coding scheme 8), there is amargin of 18 dB to establish the link.

Assume that a beam combination (ϕ_(T1), ϕ_(R1)) excites a particularAzimuth path

${l^{*}{h(\tau)}} \approx {{\alpha \left( l^{*} \right)}{\exp\left( \frac{\left( {N - 1} \right)\left( {\varphi_{T\; 1} - {\theta_{T}\left( l^{*} \right)} + {\theta_{R}\left( l^{*} \right)} - \varphi_{R\; 1}} \right)}{2} \right)}{{sinc}\left( {N\; {\Delta_{T}\left( l^{*} \right)}} \right)}{{sinc}\left( {N\; {\Delta_{R}\left( l^{*} \right)}} \right)}{\delta \left( {\tau - {\tau \left( l^{*} \right)}} \right)}}$

The magnitude and phase terms are:

G(φ_(T 1), φ_(R 1)) = α(l^(*))sinc(N(φ_(T 1) − θ_(T)(l^(*))))sinc(N(θ_(R)(l^(*)) − φ_(R 1)))${P\left( {\varphi_{T\; 1},\varphi_{R\; 1}} \right)} = {{\angle \; {\alpha \left( l^{*} \right)}} + \frac{\left( {N - 1} \right)\left( {\varphi_{T\; 1} - {\theta_{T}\left( l^{*} \right)} + {\theta_{R}\left( l^{*} \right)} - \varphi_{R\; 1}} \right)}{2}}$

With a different beam combination (ϕ_(T2), ϕ_(R2)),

${G\left( {\varphi_{T\; 2},\varphi_{R\; 2}} \right)} = {{{{\alpha \left( l^{*} \right)}}{{sinc}\left( {N\left( {\varphi_{T\; 2} - {\theta_{T}\left( l^{*} \right)}} \right)} \right)}{{sinc}\left( {N\left( {{\theta_{R}\left( l^{*} \right)} - \varphi_{R\; 2}} \right)} \right)}{P\left( {\varphi_{T\; 2},\varphi_{R\; 2}} \right)}} = {{\angle \; {\alpha \left( l^{*} \right)}} + \frac{\left( {N - 1} \right)\left( {\varphi_{T\; 2} - {\theta_{T}\left( l^{*} \right)} + {\theta_{R}\left( l^{*} \right)} - \varphi_{R\; 2}} \right)}{2}}}$

The relative gain change is:

$\frac{G\left( {\varphi_{T\; 1},\varphi_{R\; 1}} \right)}{G\left( {\varphi_{T\; 2},\varphi_{R\; 2}} \right)} = \frac{{{sinc}\left( {N\left( {\varphi_{T\; 1} - {\theta_{T}\left( l^{*} \right)}} \right)} \right)}{{sinc}\left( {N\left( {{\theta_{R}\left( l^{*} \right)} - \varphi_{R\; 1}} \right)} \right)}}{{{sinc}\left( {N\left( {\varphi_{T\; 2} - {\theta_{T}\left( l^{*} \right)}} \right)} \right)}{{sinc}\left( {N\left( {{\theta_{R}\left( l^{*} \right)} - \varphi_{R\; 2}} \right)} \right)}}$

and the relative phase change is:

${{P\left( {\varphi_{T\; 1},\varphi_{R\; 1}} \right)} - {P\left( {\varphi_{T\; 2},\varphi_{R\; 2}} \right)}} = \frac{\left( {N - 1} \right)\left( {\varphi_{T\; 1} - \varphi_{T\; 2} + \varphi_{R\; 2} - \varphi_{R\; 1}} \right)}{2}$

Assuming that the second beam-combination (ϕ_(T2), ϕ_(R2)) is refinedfor the micro-route l* which is equivalent to ϕ_(T2)≈θ_(T)(l*) andϕ_(R2)≈θ_(R) (l*), then:

$\frac{G\left( {\varphi_{T\; 1},\varphi_{R\; 1}} \right)}{G\left( {\varphi_{T\; 2},\varphi_{R\; 2}} \right)} \approx {{{sinc}\left( {N\left( {\varphi_{T\; 1} - \varphi_{T\; 2}} \right)} \right)}{{sinc}\left( {N\left( {\varphi_{R\; 2} - \varphi_{R\; 1}} \right)} \right)}}$

Now consider the effect of ground bounce. Since the Azimuth beam patternis common for both LOS and ground bounce paths, then:

${h(\tau)} \approx {\left( {{\exp\left( \frac{\left( {N - 1} \right)\left( {\Delta_{T} + \Delta_{R}} \right)}{2} \right)}{{sinc}\left( {N\; \Delta_{T}} \right)}{{sinc}\left( {N\; \Delta_{R}} \right)}} \right)\left( {{\alpha^{LOS}{\delta \left( {\tau - \tau^{LOS}} \right)}} + {\alpha^{GB}{\delta \left( {\tau - \tau^{GB}} \right)}}} \right)}$

where α^(LOS) and τ^(LOS) are the complex coefficient and relative pathdelay for the LOS path respectively, α^(GB) and τ^(GB) are the complexcoefficient and relative path delay for the ground bounce respectively.

It can be seen from the above that the above channel response can beconsidered to have two components; one based on the beamforming relativeto the AoA and AoD while the other is purely based on the physicalpropagation path. It can be verified that the relative gain change andthe phase change is the same regardless of the presence or absence ofthe ground bounce. Based on the analysis above, at least someembodiments include the following methods for mapping the beamformersinto the clusters.

Clustering Based on Array Beam-Width (Passive Method)

It can be observed in FIG. 12A that the antenna pattern response isreduced by 5 dB in less than 2.5 degrees from the peak (5 dBbeam-width=5 deg). As a result, two working beam combinations(ϕ_(T1),ϕ_(R1)) and (ϕ_(T2),ϕ_(R2)) are independent (different clusters)if:

${{{f\left( \varphi_{T\; 1} \right)} - {f\left( \varphi_{T\; 2} \right)}}} > {\frac{5\pi}{180}\mspace{14mu} {and}\mspace{14mu} {{{f\left( \varphi_{R\; 1} \right)} - {f\left( \varphi_{R\; 2} \right)}}}} > \frac{5\pi}{180}$

where f(x) maps the DFT angular frequency into physical angle ofarrival/departure.

${f(x)} = {\cos^{- 1}\left( \frac{\lambda \; x}{2\pi \; d} \right)}$

This method is passive as it doesn't require any OTA (over the air)communication to determine correlation.

Clustering Based on Mismatched Combination (Active Method)

This is an active method wherein OTA communication is required to detectcorrelation. Two combinations are correlated if this is true:

Γ(ϕ_(T1),ϕ_(R2))=1and Γ(ϕ_(T2),ϕ_(R1))=1,

where Γ(⋅) is an indicator function for the success of the beamcombination in establishing the link.

Also, the following is a good measure of correlation:

G(ϕ_(T2),ϕ_(R2))≤max(G(ϕ_(T2),ϕ_(R1)),G(ϕ_(T1),ϕ_(R2))

Based on Relative Gain and Phase Change (Active Method)

This method can use BRP (beam refinement protocol) fields for efficienttesting of the hypothesis OTA. Using BRP fields, the following metricsare calculated:

Based on the analysis in this section, the relative gain change shouldbe such that:

${\min \mspace{11mu} \left( {\frac{G\left( {\varphi_{T\; 1},\varphi_{R\; 1}} \right)}{G\left( {\varphi_{T\; 2},\varphi_{R\; 2}} \right)},\frac{G\left( {\varphi_{T\; 2},\varphi_{R\; 2}} \right)}{G\left( {\varphi_{T\; 1},\varphi_{R\; 1}} \right)}} \right)} \approx {{{sinc}\left( {N\left( {\varphi_{T\; 1} - \varphi_{T\; 2}} \right)} \right)}{{sinc}\left( {N\left( {\varphi_{R\; 2} - \varphi_{R\; 1}} \right)} \right)}}$

and the relative phase change should be:

${{P\left( {\varphi_{T\; 1},\varphi_{R\; 1}} \right)} - {P\left( {\varphi_{T\; 2},\varphi_{R\; 2}} \right)}} = {\frac{\left( {N - 1} \right)\left( {\varphi_{T\; 1} - \varphi_{T\; 2} + \varphi_{R\; 2} - \varphi_{R\; 1}} \right)}{2}.}$

In general, the above-calculations can also be computed without usingBRP, but rather, using channel estimation and path delay estimation.

Otherwise the beam-combination is not correlated.

At least some embodiments include a packet structure such that trainingfields of the packets are employed to check for correlation of beams.

FIG. 13 shows a table of measured qualities of micro-routes, accordingto an embodiment. The table includes the measured value of the linkquality between the transmitting node (either the first node or thesecond node) and the receiving node (either the first node or the secondnode). For an embodiment, the columns (1-12) of the table representdifferent beam directions (AoD) of the first (transmitting) node. For anembodiment, the rows (1-12) of the table represent different beamdirections (AoA) of the second (receiving) node.

As stated above, for an embodiment, a link quality characterization ismade at each of the beam forming directions of the transmitting and thereceiving nodes. For the table of FIG. 13, the value of “X” indicatesthe link quality is below a predetermined threshold. That is, the linkquality at these settings of the beam directions of the first and secondnodes is below a threshold.

For an embodiment, one or more of the “V”s depicted in FIG. 13 representa cluster of measurements as shown in FIG. 12B. That is, the “V” mayrepresent multiple measurements that have been clustered into a singlerepresentation. That is, each of the beam settings depicted in FIG. 3may include finer resolution settings that have been clustered into thesingle representation.

A first link quality measurement is depicted as “V1” which correspond toa beam direction setting of the first node of 9, and a beam directionsetting of the second node of 9. If the value of V1 is greater than allthe other measured values of the link quality, then these settingscorrespond with the highest quality micro-route between the first nodeand the second node. For an embodiment, this micro-route may be selectedfor communication between the first node and the second node. However,at least some embodiments include identifying other micro-routes thatmay be used if the originally selected micro-route fails.

As shown by the table of FIG. 13, other values V2 (which correspondswith the beam direction setting of 4 of the first node and the beamdirection setting of 9 of the second node), V3 (which corresponds withthe beam direction setting of 8 of the first node and the beam directionsetting of 9 of the second node), V4 (which corresponds with the beamdirection setting of 9 of the first node and the beam direction settingof 4 of the second node), V5 (which corresponds with the beam directionsetting of 9 of the first node and the beam direction setting of 8 ofthe second node), V9 (which corresponds with the beam direction settingof 1 of the first node and the beam direction setting of 4 of the secondnode), V7 (which corresponds with the beam direction setting of 2 of thefirst node and the beam direction setting of 2 of the second node), V8(which corresponds with the beam direction setting of 4 of the firstnode and the beam direction setting of 2 of the second node), V9 (whichcorresponds with the beam direction setting of 9 of the first node andthe beam direction setting of 2 of the second node), V10 (whichcorresponds with the beam direction setting of 10 of the first node andthe beam direction setting of 11 of the second node), V11 (whichcorresponds with the beam direction setting of 3 of the first node andthe beam direction setting of 11 of the second node), V12 (whichcorresponds with the beam direction setting of 3 of the first node andthe beam direction setting of 10 of the second node), V13 (whichcorresponds with the beam direction setting of 4 of the first node andthe beam direction setting of 11 of the second node), are also depicted.Anyone of these other measured values of link quality may be differentmicro-route than the micro-route corresponding with the measure linkquality of V1.

Once the table of measured values of link quality for each of theplurality of beam forming directions of the transmitting node and thereceiving node has been determined, the next act is to determine whichof these measure values of link quality correspond with differentmicro-routes. That is, some of these measure values could correspondwith a different micro-route, or some of the measured values couldcorrespond with a side-lobe of a common micro-route. It is desirable todetermine which of the measure value correspond with micro-routes andwhich correspond with side-lobes because different side-lobes of a mainlobe of a micro-route are highly correlated with the main lobe.Accordingly, if the main lobe falters (reduced signal quality causing asensed condition) or is no long available, then the side-lobes of thatmicro-route will typically not be available either. As previouslydescribed, at least some embodiments include identifying an alternatemicro-route that can be used if a selected micro-route no longerperforms as well as desired or fails.

One way to determine whether a measured value of signal qualitycorresponds with another micro-route or as a side lobe of a micro-routeis to determined where the side lobes should be located in, for example,the table of FIG. 13. The following discussion directed to lobes andexpected amplitude (measured) of side lobes can be used by at least someembodiments to distinguish between side lobe of a main lobe, andalternate (different) micro-routes.

FIG. 14 shows a primary lobe 1410 and side lobes 1420, 1430 of abeam-formed signal, according to an embodiment. As will be described,expected measured values of the side lobes (such as shown in FIG. 14) ofthe primary lobe of the beam formed transmitted signal can be used todistinguish between different micro-routes and side lobes of the tableof FIG. 13. That is, typically a side-lobe of a primary lobe has anamplitude having a power level that is less than the amplitude of thepower level of the primary lobe by an expected value. If the observedvalue of the amplitude is greater than the expected value, then it canbe concluded that a potentially observed side lobe is actually adifferent micro-route not a side lobe.

FIG. 15 shows a table of measured qualities of micro-routes, and furthershows measured qualities that could represent a primary lobe and sidelobes of a beam-formed signal, according to an embodiment. The sidelobes of the beam setting direction 9 of the first (transmitting) nodewill tend to fall within the same column. That is, the side lobes of themicro-route corresponding to the measure link quality of V1 will tend tobe located within the same column of the table as the measured value ofV1. For example, the measured link qualities of V4 and V5 may beinitially categorized as corresponding with side lobes because they arelocated in the same column as the micro-route of V1.

Further, the side lobes of the beam setting direction 9 of the first(transmitting) node will tend to fall within the same column. That is,the side lobes of the micro-route corresponding to the measure linkquality of V1 will tend to be located within the same row of the tableas the measured value of V1. For example, the measured link qualities ofV2 and V3 may be initially categorized as corresponding with side lobesbecause they are located in the same row as the micro-route of V1.

Further, for an embodiment, the measured values of V9, V7, V8, V9, V10,V11, V12, V13 are categorized as corresponding with differentmicro-routes than the micro-route of V1 because these value are alllocated within the table of FIG. 15 and FIG. 13 at different columns androws as the V1. Note, however, that some of these values maybe sidelobes of the others of these values.

FIG. 16 shows a primary lobe and side lobes of a beam-formed signal, andfurther shows a possible signal of a separate micro-route, according toan embodiment. As shown, the micro-route 1620 could be confused as aside lobe of the micro-route 1310. However, the amplitude of themicro-route 1620 is too large to be considered a side lobe. That is, aside lobe of the micro-route 1610 would be expected to have an amplitude(measured signal quality) that is lower than the amplitude of themicro-route 1610 by the expected side lobe amplitude threshold. However,the amplitude of the micro-route 1620 is greater than this amount, andaccordingly, can be designated as a separate micro-route.

FIG. 17 shows a first table that lists a measured link quality for eachof five micro-routes, and lists a level of correlation with a firstmicro-route take at a time T1, a second table that lists a measured linkquality for each of the five micro-routes, and lists a level ofcorrelation with a first micro-route take at a time T2, according to anembodiment. As previously described, as the conditions of the wirelessnetwork changes, the level of correlation between micro-routes canchange. For at least some embodiments, the level of correlation betweenthe different identified micro-routes is monitored (measured) over time.Further, conditions can be sensed to determine whether to re-measure thelevel of correlation between micro-routes.

For an embodiment, determining the level of correlation between a firstmicro-route and a second micro-route includes determining how much asevent or sensed condition effects both of the first micro-route and thesecond route. The more correlated the first micro-route is to the secondmicro-route, the more similar the effect the event or the sensedcondition has on both of the first micro-route and the secondmicro-route. Further, the less correlated the first micro-route is tothe second micro-route, the less the effect the event or the sensedcondition has on both of the first micro-route and the secondmicro-route.

As previously described, for at least some embodiments, if a linkcondition (for example, a failure of the link) of a micro-route beingused for wireless communication is sensed or determined, a newmicro-route is selected based on the level of correlation of the newmicro-route with the micro-route being used. For an embodiment, the lesscorrelated the new micro-route is with the micro-route being used, themore likely the chances are that the new micro-route will be selected ifthe link condition (for example, a failure of the link) of a micro-routebeing used for wireless communication is sensed or determined.

As previously described, for at least some embodiments, the micro-routesbetween the transmitting node and the receiving node are monitored overtime. That is, the performance of the micro-routes is re-characterizedrepeatedly over time. For at least some embodiments, the level ofcorrelation between the different micro-routes is determined bydetermining variations in the performance (for example, measured linkquality) between the different micro-routes over the repeatedcharacterizations. That is, the correlation determination includesdetermining whether the performance of the different micro-routeschanges similarly or differently over time. The more correlateddifferent micro-routes are, the more similar the variations in theperformance of the micro-routes. The less correlated the differentmicro-routes are, the less similar the variation in the performance ofthe micro-routes. Statistical processes can be used to determine thesimilarity or difference between different micro-routes over time bycomparing the performance of the different micro-route over the repeatedcharacterization of the performance of the different micro-routes overtime.

As previously described, for at least some embodiments, the correlationbetween different micro-routes is determined by determining how theperformance of the different micro-routes is affected by a change in anetwork condition. Exemplary network conditions include the introductionor the elimination of one or more interfering signals, a change innetwork topology (such as, the addition or removal of a network node, orthe change of location of a network node), a change in the environmentaround or surrounding the wireless network (such as, movement of,addition of, or subtraction of a physical object). If the differentmicro-routes are correlated, then the change in the network conditionwill change the performance of the different micro-routes similarly. Ifthe different micro-routes are not correlated, then the change in thenetwork condition will change the performance of the differentmicro-routes differently. Statistical processes can be used to determinethe similarity or difference between different micro-routes with changesin the network conditions.

For an embodiment a matrix is generated wherein the elements of thematrix indicate the correlation between a micro-route represented by rowIi with micro-route represented by column j.

For an embodiment, the correlation between a first micro-route and asecond micro-route is determined based on the angular difference betweenthe AoD at the transmitter for the first micro-route and for the secondmicro-route, and/or the angular difference between the AoA at thereceiver for the first micro-route and for the second micro-route. Thatis, the correlation between the first micro-route and the secondmicro-route is determined as a function of the difference between theAoD at the transmitter for the first micro-route and the AoD at thetransmitter for the second micro-route, and/or as a function of thedifference between the AoD at the transmitter for the first micro-routeand the AoD at the transmitter for the second micro-route

Correlated Micro-Routes and Back Up Micro-Routes

For at least some embodiments, two micro-routes are consideredcorrelated if:

Pr(uR[k]=1|uR[i]=0)≤ρPr(uR[k]=1)

where ρ is the correlation detection threshold. An exemplary ρ is:ρ=0.7.

A useful metric to determine a back-up micro-routek*=arg maxPr(uR[k]=1|uR[i]=0).

For an embodiment, a set of top independent micro-routes for micro-routei is given as:

S ₁ ={k ₁ . . . k _(N)}

such that:

Pr(uR[k ₁]=1|uR[i]=0)≥Pr(uR[k ₂]=1|uR[i]=0) . . . ≥Pr(uR[k_(N)]=1|uR[i]=0)

and

Pr(uR[k _(N)]=1|uR[i]=0)≥Pr((uR[j]=1|uR[i]=0))∀j∉S _(i).

When a set of micro-routes is communicated to the link, the link hasmore flexibility in determining the best back-up from the set based onthe recent channel conditions:

Another metric to determine a back-up micro-routes is solely based onthe marginal distribution:

k*=arg max Pr(uR[k]=1)

For at least some embodiments, the transmitter of the link communicatesthe list of back-up micro-routes to its receiver. Further instead ofsolely relying on the E2E (end-to-end) statistics at, for example, acentral controller, the backup micro-route can be determined based on aweighted combination of one or more of E2E computation of conditionalprobability, the current capacity of the micro-route (at the linklevel), an angular distance to the existing micro-route (the farther thebetter). Note that each of the metrics individually is one of thespecial cases of the weighted metric.

Time Correlation

For at least some embodiments, another important statistical analysis isthe correlation of micro-route across time. This analysis can deducesome of the following ON-OFF behavior of micro-routes. First,distribution nodes near, for example, a traffic intersection undergo aperiodic pattern in which a few micro-routes are blocked or createdduring a finite time window. For example, at an intersection dependingon the lights, the traffic can go parallel/perpendicular to thedirection of the link. Second, bus parking during night.

To compute the probabilities, at least some embodiments includefiltering observations based on the time mask. Based on the initialobservations, a controller can trigger time-specific procedures toconfirm or reject the hypothesis. For example, when the computedcorrelation is close to the threshold, the controller can trigger a linklevel procedure using BRP fields to compute relative magnitude andphase.

FIG. 18 shows a first node and a second node of a wireless network,wherein micro-routes between the first node and the second node arecharacterized in two transmit and receive directions, according to anembodiment. That is, FIG. 11B describes characterizing the micro-linkswhile the node 1110 is transmitting and the node 1120 is receiving.However, as shown in FIG. 18, the relationship between the nodes 1110,1120 can be reversed during the characterization process.

For an embodiment, a matrix or table of measured qualities ofmicro-routes similar to the table of FIG. 17 is generated in bothtransmit and receive direction, resulting in more than one matrix ortable. That is, for example, a matrix or table of measured qualities ofmicro-routes is generated when the node 1110 is transmitting and thenode 1120 is receiving, and another matrix or table of measuredqualities of the micro-routes is generated when the node 1110 isreceiving and the node 1120 is transmitting. For an embodiment, the oneor more matrices of the qualities of the micro-routes are combined.

For an embodiment, combining the matrices that are generated in the twodifferent link directions include identifying clusters that are commonto both of the matrices, and only including the common clusters withinthe combined matrix. That is, clusters of one matrix that are not alsowithin the other matrix are eliminated from the combined matrix.

FIG. 19 is a flow chart that includes acts of a method of characterizingmicro-links between a first node and a second node, according to anembodiment. A first step 1910 includes directing a first beam formed bya plurality of antennas of the first node to a plurality of directions.A second step 1920 includes directing a second beam formed by aplurality of antennas of the second nodes to a plurality of directionsfor each of the plurality of directions of the first beam. A third step1930 includes characterizing a link quality between the first node andthe second node for each of the plurality of beam directions of thefirst beam and each of the plurality of beam directions of the secondbeam.

For at least some embodiments, characterizing the link quality includesdetermining whether the link quality is better than a threshold. For atleast some embodiment, a known signal (that is, characteristics of thesignal, such as, the transmit signal power level) is transmitted fromone of the first node or the second node, and received at the other ofthe first or second node. For an embodiment, the received signalstrength of the received signal indicates the link quality of themicro-route. For an embodiment, only link qualitied better than athreshold are recorded and utilized.

At least some embodiments further include forming a matrix that includesthe characterized link quality for each of the each of the plurality ofbeam directions of the first beam and each of the plurality of beamdirections of the second beam. For an embodiment, the matrix includesentries that represent 2 dimensions of space as defined by thedirections of the first beam and the directions of the second beam.Further, for an embodiment, the matrix includes entries that represent 3dimensions of space.

At least some embodiments further include identifying one or moreclusters of characterized link qualities that include characterized linkqualities greater than a threshold.

At least some embodiments further include classifying the one or moreclusters. As previously described, for at least some embodiments the oneor more clusters are classified as at least one of side lobes ormicro-routes.

At least some embodiments further include determining a level ofcorrelation between each of the micro-routes.

At least some embodiments further include monitoring link conditionsbetween the first node and the second node, and re-characterizing atleast a subset of the one or more micro-routes between a first node anda second node if the monitored link conditions are determined to changeby more than a threshold. For an embodiment, detected changes in signalqualities of signals communicated between the first node and the secondnode are used for determining when to re-characterize the micro-routesbetween the first node and the second node.

FIG. 20 is a flow chart that includes acts of a method of clusteringmeasured signal qualities of micro-routes, according to an embodiment. Afirst step 2010 includes determining link quality measurements between atransmitting node and a receiving node for multiple AoD of thetransmitting node and for multiple AoA of the receiving node. A secondstep 2020 includes identifying link quality measurements from thedetermined link quality measurements having a quality better than aquality threshold. A third step 2030 includes clustering link qualitymeasurements of greater than the threshold and within an AoD rangethreshold and within an AoA as a single micro-link. That is, as shown inFIG. 12A, a single micro-route may be formed between the transmittingnode and the receiving nodes for a small (threshold) range of variationsof the AoD and AoA. For an embodiment, the measured link qualities forsmall (less than a threshold) of variations of AoD and AoA having a linkquality better than the quality threshold are clustered, and designatedas a single micro-route. Once clustered, the described embodimentfurther includes classifying the different identified clusters as aside-lobes if each other or as separate micro-links.

FIG. 21 is a flow chart that includes acts of a method selectingmicro-links for communication between a first node and a second node ofa wireless network, according to an embodiment. A first step 2110includes wirelessly communicating between a first node and a second nodethrough a wireless link formed by at least one micro-route. A secondstep 2120 includes determining a condition of the at least onemicro-route. For an embodiment, the condition of the at least onemicro-route includes a quality of the micro-route. For an embodiment,determining the condition includes transmitting a signal through themicro-link and determining a received signal quality or a receive signalamplitude at the receiving node. For an embodiment, if the quality oramplitude of the receive signal is below a threshold, then themicro-route condition is determined to be a link failure, and a new ordifferent micro-route is selected because of the detected failure of theat least one micro-route. For at least some embodiments, the signalquality includes a measurement of at least one of SNR (signal to noiseratio), PER (packet error rate), or BER (bit error rate) of signalscommunicated from the transmitting node to the receiving node throughthe micro-route.

A third step 2130 includes selecting at least one other micro-route forcommunication between the first node and the second node based on alevel of correlation between the at least one micro-route and the atleast one other micro-route. As previously described, the correlationbetween different micro-routes can be monitored over time. For at leastsome embodiments, the correlations between different micro-routes isstored, and retrieved when a new micro-route is to be selected due tothe failure (sensed condition) of a micro-route being used tocommunication information between the transmitting node and thereceiving node.

For at least some embodiment, the at least one micro-route and the atleast one other micro-route are selected from a plurality ofpredetermined micro-routes. For an embodiment, the predeterminemicro-routes are determined by characterizing one or more micro-routesbetween a first node and a second node. For example, for an embodiment,the one or more micro-routes between the first node and the second nodeare determined through a characterization process, and stored in memory.The at least one micro-route is accessed from memory and used forwirelessly communicating between the first node and the second node.Upon detecting a condition, such as, failure of the at least onemicro-route, the at least one other micro-route is retrieved frommemory, and selected for wireless communication between the first nodeand the second node based on the level of correlation (typically, theleast correlated, or correlated less than a threshold or desired amount)between the at least one micro-route and the at least one othermicro-route.

As previously described, for an embodiment, characterizing one or moremicro-routes between a first node and a second node includes directing afirst beam formed by a plurality of antennas of the first node to aplurality of directions, directing a second beam formed by a pluralityof antennas of the second nodes to a plurality of directions for each ofthe plurality of directions of the first beam, and characterizing a linkquality between the first node and the second node for each of theplurality of beam directions of the first beam and each of the pluralityof beam directions of the second beam. For at least some embodiment, thecharacterized one or more micro-routes are stored in the memory.

Pattern Detection

FIG. 22 shows a transmitting node 2210 and a receiving node 2220 locatedproximate to a traffic intersection, and implementation of patterndetection that is used for micro-route characterization and selection,according to an embodiment. For an embodiment, the nodes 2210, 2220 areconnected through one or more networks to an upstream cloud server.Accordingly, the cloud server performs or has access to thecharacterization and selection of micro-routes between the nodes 2210,2220. For an embodiment, collected information relating to thecharacterization and selection of micro-routes is used for determiningpatterns in operations and changes in the environmental around the nodes2210, 2220. For example, a bus creating/blocking some micro-routesduring a particular time window can be mined out of data of thecollected information. Further, from the micro-route reports it ispossible to classify whether a link (of the micro-routes) lies at a busyroad with frequent environmental changes or in a quite street. Based onthe classification, different parameters for link adaptation can beselected. For example, based on the periodic micro-route training, itcan be deduced whether the link is undergoing more frequent fading/polesway/foliage sway/blockage. Based on the classification, conservative oraggressive parameters can be set. Further, the micro-route training canbe adaptive based upon sensed conditions of the wireless network.

Cloud Server and Node Controller

FIG. 23 shows a transmitting node 2320, a receiving node 2330, and acloud server 2310, according to an embodiment. As shown, thetransmitting node 2320, and the receiving node 2330 are connected to thecloud server 2310. This connection can be through one or more networksthat provide a communication path between the cloud server 2310 and thenodes 2320, 2330.

As previously described, the cloud server 2310 can be connected to manydifferent nodes of the wireless network, and can collect informationrelated to the nodes of the wireless network. For an embodiment, thecloud server 2310 performs at least one of the determination ofconditions of one or more one micro-routes between the nodes, orselection one or more different micro-routes for communication betweenthe first node and the second node based on a level of correlationbetween the one or more micro-routes and the one or more differentmicro-routes. For an embodiment, the cloud server 2310 performs thecharacterization of one or more micro-routes between a first node and asecond node.

For at least some embodiments, the cloud server 2310 further performs atleast one of the clustering of the measured link qualities intomicro-routes, classifying the micro-routes, and determining a level ofcorrelation between the identified micro-routes.

The transmitting node 2320 includes multiple RF (radio frequency) chainswhich are connected to multiple antennas of the transmitting node 2320.As previously described, the multiple antennas generate a directionalbeam which is directionally controlled, for example, by controlling theamplitude and phase of the signals transmitted by the multiple antennas.

For at least some embodiments, a node controller 2325 of thetransmitting node and/or the cloud server 2310 aid in thecharacterization and determination of micro-route available for wirelesscommunication between the transmitting node 2320 and the receiving node2330. Once the micro-routes have been characterized and determined, themicro-routes may be stored in memory 2390.

Further, the node controller 2325 of the transmitting node and/or thecloud server 1310 aid in determination of the correlation between themicro-route available for wireless communication between thetransmitting node 2320 and the receiving node 2330. Once thecorrelations between the micro-routes have been determined, thecorrelations may be stored in memory 2390.

The node controller 2325 of the transmitting node 2320 can access thestored micro-routes from the memory 2390 when determining whichmicro-routes to utilize for wirelessly communicating with the receivingnode 2330. Further, the node controller 2335 of the transmitting node2320 can access the stored correlations between the micro-routes fromthe memory 2390 when determining which micro-routes to select upondetermining that the present micro-route being used satisfies acondition (such as, a failure in performance).

The receiving node 2330 also includes multiple RF chains for themultiple antennas of the receiving node 2330. For an embodiment, thereceiving node 2330 preforms link quality measurements 2338 during thedetermination and characterization of the micro-links between thetransmitting node 2320 and the receiving node 2330. For an embodiment,after the receiving node 2330 preforms link quality measurements 2338,the link quality measurements 2338 are stored in the memory 2390 forfuture access. Further, for at least some embodiments, the correlationdeterminations between the characterized micro-links are stored in thememory 2390 as well.

Embodiments according to the invention are in particular disclosed inthe attached claims directed to a method and a system, wherein anyfeature mentioned in one claim category, e.g. method, can be claimed inanother claim category, e.g. system, as well. The dependencies orreferences back in the attached claims are chosen for formal reasonsonly. However any subject matter resulting from a deliberate referenceback to any previous claims (in particular multiple dependencies) can beclaimed as well, so that any combination of claims and the featuresthereof is disclosed and can be claimed regardless of the dependencieschosen in the attached claims. The subject-matter which can be claimedcomprises not only the combinations of features as set out in theattached claims but also any other combination of features in theclaims, wherein each feature mentioned in the claims can be combinedwith any other feature or combination of other features in the claims.Furthermore, any of the embodiments and features described or depictedherein can be claimed in a separate claim and/or in any combination withany embodiment or feature described or depicted herein or with any ofthe features of the attached claims.

In an embodiment according to the invention, a method may comprisewirelessly communicating between a first node and a second node througha wireless link formed by at least one micro-route, determining acondition of the at least one micro-route, and selecting at least oneother micro-route for communication between the first node and thesecond node based on a level of correlation between the at least onemicro-route and the at least one other micro-route after determining thecondition.

A node may especially be any kind of connection point, redistributionpoint or communication endpoint, as for example a data communicationequipment (e.g. modem, hub, bridge, switch) or a data terminal equipment(e.g. digital telephone handset, printer, host computer, router,workstation or server). In particular a node may be a wireless routerand/or a wirelessly connected mobile communication device.

Determining the level of correlation between the first micro-route andthe second micro-route may include determining how much an event orsensed condition effects both of the first micro-route and the secondroute, and the more similar the effect the event or sensed condition hason both, the more correlated they are. As previously described, for atleast some embodiments, the micro-routes between the transmitting nodeand the receiving node are monitored over time. That is, the performanceof the micro-routes is re-characterized repeatedly over time. For atleast some embodiments, the level of correlation between the differentmicro-routes is determined by determining variations in the performance(for example, measured link quality) between the different micro-routesover the repeated characterizations. That is, the correlationdetermination includes determining whether the performance of thedifferent micro-routes changes similarly or differently over time. Themore correlated different micro-routes are, the more similar thevariations in the performance of the micro-routes. The less correlatedthe different micro-routes are, the less similar the variation in theperformance of the micro-routes. Statistical processes can be used todetermine the similarity or difference between different micro-routesover time by comparing the performance of the different micro-route overthe repeated characterization of the performance of the differentmicro-routes over time.

The condition may be one or more of the following: the performance; theintroduction or the elimination of one or more interfering signals; achange in network topology; a change in the physical environment aroundor surrounding the wireless network; the failure of a link; the signalquality.

In an embodiment according to the invention, a method may comprisecharacterizing a plurality of micro-routes between a first node and asecond node, wherein the plurality of micro-routes includes the at leastone micro-route and the at least one other micro-route, comprisingdirecting a first beam formed by a plurality of antennas of the firstnode to a plurality of directions, for each of the plurality ofdirections of the first beam, directing a second beam formed by aplurality of antennas of the second nodes to a plurality of directions,and characterizing a link quality between the first node and the secondnode for each of the plurality of beam directions of the first beam andeach of the plurality of beam directions of the second beam.

Characterizing the link quality may comprise determining whether thelink quality is better than a threshold.

In an embodiment according to the invention, a method may compriseforming a matrix that includes the characterized link quality for eachof the each of the plurality of beam directions of the first beam andeach of the plurality of beam directions of the second beam.

In an embodiment according to the invention, a method may compriseidentifying one or more clusters of characterized link qualities thatinclude characterized link qualities greater than a threshold.

In an embodiment according to the invention, a method may compriseclassifying the one or more clusters.

The one or more clusters may be classified as at least one of side lobesor micro-routes.

In an embodiment according to the invention, a method may comprisedetermining a level of correlation between each of the micro-routes.

The level of correlation may be determined based on the difference inAoD (angle of departure) at the transmitting node and AoA (angle ofarrival) at the receiving node between each of the micro-routes.

In an embodiment according to the invention, a method may comprisemonitoring link conditions between the first node and the second node,and re-characterizing at least a subset of the plurality of micro-routesbetween a first node and a second node if the monitored link conditionsare determined to change by more than a threshold.

An upstream cloud server connected to the first node and the second nodemay perform a portion of at least one of the characterizing one or moremicro-routes between the first node and the second node, or theselecting at least one other micro-route for communication between thefirst node and the second node.

In an embodiment according to the invention, a wireless network maycomprise a first node, a second node, wherein the first node wirelesslycommunicates with the second node through a wireless link formed by atleast one micro-route, and a controller, wherein the controller isoperative to determine a condition of the at least one micro-route, andselect at least one other micro-route for communication between thefirst node and the second node based on a level of correlation betweenthe at least one micro-route and the at least one other micro-routeafter determining the condition.

In an embodiment according to the invention, a wireless network maycomprise a first node, a second node, wherein the first node wirelesslycommunicates with the second node through a wireless link formed by atleast one micro-route, and a controller, wherein the controller isoperative to determine a condition of the at least one micro-route,select at least one other micro-route for communication between thefirst node and the second node based on a level of correlation betweenthe at least one micro-route and the at least one other micro-routeafter determining the condition.

Determining the level of correlation between the first micro-route andthe second micro-route may include determining how much an event orsensed condition effects both of the first micro-route and the secondroute, and the more similar the effect the event or sensed condition hason both, the more correlated they are.

The condition may be one or more of the following: the performance; theintroduction or the elimination of one or more interfering signals; achange in network topology; a change in the physical environment aroundor surrounding the wireless network; the failure of a link; the signalquality.

The controller may be operative to characterize a plurality ofmicro-routes between a first node and a second node, wherein theplurality of micro-routes includes the at least one micro-route and theat least one other micro-route, comprising directing a first beam formedby a plurality of antennas of the first node to a plurality ofdirections, for each of the plurality of directions of the first beam,directing a second beam formed by a plurality of antennas of the secondnodes to a plurality of directions, and characterize a link qualitybetween the first node and the second node for each of the plurality ofbeam directions of the first beam and each of the plurality of beamdirections of the second beam.

Characterizing the link quality may comprise determining whether thelink quality is better than a threshold.

The controller may be operative to form a matrix that includes thecharacterized link quality for each of the each of the plurality of beamdirections of the first beam and each of the plurality of beamdirections of the second beam.

The controller may be operative to identify one or more clusters ofcharacterized link qualities that include characterized link qualitiesgreater than a threshold.

The controller may be operative to classify the one or more clusters.

The one or more clusters may be classified as at least one of side lobesor micro-routes.

The controller may be operative to determine a level of correlationbetween each of the micro-routes.

The controller may be operative to monitor link conditions between thefirst node and the second node, and re-characterize at least a subset ofthe one or more micro-routes between a first node and a second node ifthe monitored link conditions are determined to change by more than athreshold.

In a further embodiment according to the invention, one or morecomputer-readable non-transitory storage media embody software that isoperable when executed to perform a method according to the invention orany of the above mentioned embodiments.

In a further embodiment according to the invention, a system comprises:one or more processors; and at least one memory coupled to theprocessors and comprising instructions executable by the processors, theprocessors operable when executing the instructions to perform a methodaccording to the invention or any of the above mentioned embodiments.

In a further embodiment according to the invention, a computer programproduct, preferably comprising a computer-readable non-transitorystorage media, is operable when executed on a data processing system toperform a method according to the invention or any of the abovementioned embodiments.

Embodiments of the subject matter and the operations described in thisspecification can be implemented in digital electronic circuitry, or incomputer software, firmware, or hardware, including the structuresdisclosed in this specification and their structural equivalents, or incombinations of one or more of them. Embodiments of the subject matterdescribed in this specification can be implemented as one or morecomputer programs, i.e., one or more modules of computer programinstructions, encoded on a computer storage medium for execution by, orto control the operation of, data processing apparatus.

A computer storage medium can be, or can be included in, acomputer-readable storage device, a computer-readable storage substrate,a random or serial access memory array or device, or a combination ofone or more of them. Moreover, while a computer storage medium is not apropagated signal, a computer storage medium can be a source ordestination of computer program instructions encoded in an artificiallygenerated propagated signal. The computer storage medium also can be, orcan be included in, one or more separate physical components or media(e.g., multiple CDs, disks, or other storage devices). The operationsdescribed in this specification can be implemented as operationsperformed by a data processing apparatus on data stored on one or morecomputer-readable storage devices or received from other sources.

The term “processor” encompasses all kinds of apparatus, devices, andmachines for processing data, including by way of example a programmableprocessor, a computer, a system on a chip, or multiple ones, orcombinations, of the foregoing. The apparatus can include specialpurpose logic circuitry, e.g., an FPGA (field programmable gate array)or an ASIC (application-specific integrated circuit). The apparatus alsocan include, in addition to hardware, code that creates an executionenvironment for the computer program in question, e.g., code thatconstitutes processor firmware, a protocol stack, a database managementsystem, an operating system, a cross-platform runtime environment, avirtual machine, or a combination of one or more of them. The apparatusand execution environment can realize various different computing modelinfrastructures, such as web services, distributed computing and gridcomputing infrastructures.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages and declarative orprocedural languages, and it can be deployed in any form, including as astand-alone program or as a module, component, subroutine, object, orother unit suitable for use in a computing environment. A computerprogram may, but need not, correspond to a file in a file system. Aprogram can be stored in a portion of a file that holds other programsor data (e.g., one or more scripts stored in a markup languagedocument), in a single file dedicated to the program in question, or inmultiple coordinated files (e.g., files that store one or more modules,sub-programs, or portions of code). A computer program can be deployedto be executed on one computer or on multiple computers that are locatedat one site or distributed across multiple sites and interconnected by acommunication network.

The processes and logic flows described in this specification can beperformed by one or more programmable processors executing one or morecomputer programs to perform actions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA or an ASIC.

Processors suitable for the execution of a computer program include, byway of example, both general and special-purpose microprocessors and anyone or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read-only memory ora random access memory or both. The essential elements of a computer area processor for performing actions in accordance with instructions andone or more memory devices for storing instructions and data. Generally,a computer will also include, or be operatively coupled to receive datafrom or transfer data to, or both, one or more mass storage devices forstoring data, e.g., magnetic disks, magneto-optical disks, or opticaldisks. Devices suitable for storing computer program instructions anddata include all forms of nonvolatile memory, media and memory devices,including by way of example semiconductor memory devices, e.g., EPROM,EEPROM, and flash memory devices; magnetic disks, e.g., internal harddisks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROMdisks. The processor and the memory can be supplemented by, orincorporated in, special-purpose logic circuitry.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thescope of the invention. Accordingly, the invention is not limited exceptas by the appended claims.

Although specific embodiments have been described and illustrated, theembodiments are not to be limited to the specific forms or arrangementsof parts so described and illustrated. The described embodiments are toonly be limited by the claims.

I/We claim:
 1. A wireless node, comprising: a plurality of antennasoperative to form a plurality of wireless beams directed to a pluralityof targets, wherein a direction of each of the plurality of wirelessbeams is controlled by selecting a phase and amplitude adjustment of acommunication signal communicated through each of the plurality ofantennas; a memory, the memory including a first portion and a secondportion, wherein phase and amplitude settings for each of the pluralityof targets are stored in the first portion, and wherein alternate phaseand amplitude setting are dynamically store in the second portion; and acontroller, the controller operative to: access phase and amplitudesettings from the first portion of the memory when the wireless node iscommunicating with one or more of the plurality of targets; utilize thesecond portion of memory for storing and accessing the alternate phaseand amplitude settings when testing wireless communication with one ormore of the plurality of targets.
 2. The wireless node of claim 1,wherein the controller is further operative to replace phase andamplitudes settings of the first portion of the memory for one or moreof the plurality of targets when alternate phase and amplitude settingsof the second portion of the memory are determined to be better duringthe testing of the wireless communication with one or more of theplurality of targets.
 3. The wireless node of claim 1, furthercomprising selecting the alternate phase and amplitude settings to tunea beam directed to a first target by a first threshold, and storing thealternate phase and amplitude settings in the second portion of thememory.
 4. The wireless node of claim 3, wherein the wireless nodefurther operates to transmit a first training signal while the beamdirected to the first target is tuned by the first threshold.
 5. Thewireless node of claim 4, wherein the wireless node further operates toreceive a wireless link quality indicator from the first targetindicating a quality of reception of the first training signal.
 6. Thewireless node of claim 4, wherein the target node decodes a header of apacket received from the wireless node, and determines a number oftraining signals included within the packet, and a number of receivebeamforming directions of the target node for the number of trainingsignals.
 7. The wireless node of claim 5, wherein the wireless node isfurther operative to replace the phase and amplitude setting for thefirst target within the first portion of the memory with the selectedalternate phase and amplitude settings when the received link qualityindicator indicates that the selected alternate phase and amplitudesettings provides a better quality wireless link between the wirelessnode and the first target than the phase and amplitude setting for thefirst target currently stored in the first portion of the memory.
 8. Thewireless node of claim 1, wherein wireless communication of the wirelessnode includes frames, wherein the frame include time slots, and whereinthe alternate phase and amplitude settings are tested during selectedtime slots of selected frames.
 9. The wireless node of claim 8, whereinthe testing of the alternate phase and amplitude settings is periodic.10. The wireless node of claim 8, wherein the testing of the alternatephase and amplitude settings is adaptively performed when a wirelesslink between the wireless node and one or more of the targets is sensedto be lower than a threshold.
 11. The wireless node of claim 1, whereinthe controller is further operative to: retrieve from the first portionof the memory phase and amplitude settings associated with a firstmicro-route of a plurality of predetermined micro-routes between thewireless node and a target node of the plurality of targets; transmitpackets in a first transmit beamforming direction associated with thefirst micro-route between the wireless node and the target node;retrieve from the first portion of the memory phase and amplitudesettings associated with a second micro-route of a plurality ofpredetermined micro-routes between the wireless node and the targetnode; transmit packets including one or more training signals in asecond transmit beamforming direction associated with the secondmicro-route of the plurality of predetermined micro-routes that isdifferent than the first transmit beamforming direction associated withthe first micro-route; and receive feedback from the target nodeindicating that the second micro-route corresponding with atransmit/receive beamforming pair of the second transmit beamformingdirection and a second receive beamforming direction provides a bettercommunication link than a transmit/receive beamforming pair of the firsttransmit beamforming direction and a first receive beamforming directionof the first micro-route.
 12. The wireless node of claim 11, wherein thecontroller is further operative to: retrieve from the second portion ofthe memory, a phase and amplitude settings corresponding with a firstfine-tuned direction of a transmit beamforming direction associated witha micro-route; transmit a first training signal of the plurality oftraining signals within the at least one transmit packet in the firstfined-tuned direction of the transmit beamforming direction associatedwith the micro-route, wherein the first fine-tune direction deviates adirection of the transmit beamforming direction by a first threshold;retrieve from the second portion of the memory, a phase and amplitudesettings corresponding with a second fine-tuned direction of a transmitbeamforming direction associated with a micro-route; transmit a secondtraining signal of the plurality of training signals within the at leastone transmit packet in the second fine-tuned direction of the transmitbeamforming direction associated with the micro-route, wherein thesecond fine-tune direction deviates a direction of the transmitbeamforming direction by a second threshold; receive feedback from thetarget node indicating a communication link quality corresponding withone or more of first fine-tuned direction of the transmit beamformingdirection or the second fine-tuned direction of the transmit beamformingdirection.
 13. A method, comprising: forming, by a plurality of antennasof a wireless node, a plurality of wireless beams directed to aplurality of targets, wherein a direction of each of the plurality ofwireless beams is controlled by selecting a phase and amplitudeadjustment of a communication signal communicated through each of theplurality of antennas; storing, in a memory, the memory including afirst portion and a second portion, phase and amplitude settings foreach of the plurality of targets in the first portion, and dynamicallystoring alternate phase and amplitude setting in the second portion;accessing, by a controller, phase and amplitude settings from the firstportion of the memory when the wireless node is communicating with oneor more of the plurality of targets; utilizing, by the controller, thesecond portion of memory for storing and accessing the alternate phaseand amplitude settings when testing wireless communication with one ormore of the plurality of targets.
 14. The method of claim 13, furthercomprising replacing phase and amplitudes settings of the first portionof the memory for one or more of the plurality of targets when alternatephase and amplitude settings of the second portion of the memory aredetermined to be better during the testing of the wireless communicationwith one or more of the plurality of targets.
 15. The method of claim14, further comprising selecting the alternate phase and amplitudesettings to tune a beam directed to a first target by a first threshold,and storing the alternate phase and amplitude settings in the secondportion of the memory.
 16. The method of claim 15, further comprisingtransmitting a first training signal while the beam directed to thefirst target is tuned by the first threshold.
 17. The method of claim19, further comprising receiving, by the wireless node, a wireless linkquality indicator from the first target indicating a quality ofreception of the first training signal.
 18. The method of claim 19,further comprising, decoding, by the target node, a header of a packetreceived from the wireless node, and determines a number of trainingsignals included within the packet, and a number of receive beamformingdirections of the target node for the number of training signals. 19.The method of claim 18, further comprising, replacing by the wirelessnode, the phase and amplitude setting for the first target within thefirst portion of the memory with the selected alternate phase andamplitude settings when the received link quality indicator indicatesthat the selected alternate phase and amplitude settings provides abetter quality wireless link between the wireless node and the firsttarget than the phase and amplitude setting for the first targetcurrently stored in the first portion of the memory.
 20. The method ofclaim 13, further comprising: retrieving, by the controller of thewireless node, from the first portion of the memory phase and amplitudesettings associated with a first micro-route of a plurality ofpredetermined micro-routes between the wireless node and a target nodeof the plurality of targets; transmitting packets in a first transmitbeamforming direction associated with the first micro-route between thewireless node and the target node; retrieving, by the controller of thewireless node, from the first portion of the memory phase and amplitudesettings associated with a second micro-route of a plurality ofpredetermined micro-routes between the wireless node and the targetnode; transmitting packets including one or more training signals in asecond transmit beamforming direction associated with the secondmicro-route of the plurality of predetermined micro-routes that isdifferent than the first transmit beamforming direction associated withthe first micro-route; and receiving, by the controller of the wirelessnode, feedback from the target node indicating that the secondmicro-route corresponding with a transmit/receive beamforming pair ofthe second transmit beamforming direction and a second receivebeamforming direction provides a better communication link than atransmit/receive beamforming pair of the first transmit beamformingdirection and a first receive beamforming direction of the firstmicro-route.